Review and Proposal for a Classification System of Soft Robots Inspired by Animal Morphology.

The aim of this article is to propose a bio-inspired morphological classification for soft robots based on an extended review process. The morphology of living beings that inspire soft robotics was analyzed; we found coincidences between animal kingdom morphological structures and soft robot structures. A classification is proposed and depicted through experiments. Additionally, many soft robot platforms present in the literature are classified using it. This classification allows for order and coherence in the area of soft robotics and provides enough freedom to expand soft robotics research.

Zoometric and ethnological characterization of the colombian creole donkey in Sucre, Colombia

In Colombia, works performed with the colombian creole donkey (CCD) have shown a possible danger of extinction. The above, associate with an alarming decrease in its inventory and a reduction in genetic diversity. Thus, morphological characterization could be the first step for future conservation plans to conduct a repopulation. Therefore, this work aimed to characterize the zoometric and ethnological traits of CCD in five natural subregions of the department of Sucre. 20 males from each of the natural subregions from Sucre (Golfo de Morrosquillo: GM, Montes de María: MM, Mojana: MO, San Jorge: SJ, Sabanas: SA) with an age average of 4.7 ± 1.0 years old and weight estimated between 126.0 ± 19.4 kg were recorded and were submitted to 28 morphometric measurements. Descriptive statistics, analysis of variance between subregions, and hierarchical grouping for statistical analysis were performed. Also, five ethnological indices and five productive indices were estimated. The results showed that most of the zoometric variables varied significantly between subregions. The values assessed were similar to other creole donkey breeds. The hierarchical grouping analysis allowed the creation of two groups with geographic proximity. The structural homogeneity and morphostructural harmony found within the subregions were medium-low. However, when analyzing all the CCD measurements together, medium to high morphostructural uniformity and harmony were evidenced. The ethnological indices allow us to classify the CCD as a longlinear, hypermetric, dolichocephalic, and concavilinear animal. In addition, the productive indices indicated that the CCD is a proportionate donkey, with good poise and aptitude for work.

Es posible que el asno criollo colombiano (ACC) se encuentre en peligro de extinción. La alarmante disminución de su inventario está reduciendo la diversidad genética. Así, la caracterización morfológica es un primer paso en futuros planes de conservación, con el objetivo de repoblación; por tanto, el objetivo de esta investigación fue caracterizar zoométricamente y etnológicamente el ACC, de las cinco subregiones naturales del departamento de Sucre. En 20 machos de cada una de las subregiones naturales del departamento de Sucre (Golfo de Morrosquillo: GM, Montes de María: MM, Mojana: MO, San Jorge: SJ, Sabanas: SA), con edad promedio de 4,7 ± 1,0 años y peso promedio estimado de 126,0 ± 19,4kg, se registraron 28 medidas morfométricas. En el análisis de datos, se consideró la estadística descriptiva, el análisis de varianza entre subregiones, análisis de agrupación jerárquica. También, se estimaron cinco índices etnológicos y cinco índices productivos. La mayoría de las variables zoométricas variaron significativamente entre subregiones, con valores similares a otras razas criollas. El análisis de agrupación jerárquica formó dos grupos con cercanía geográfica. La homogeneidad estructural y la armonía morfoestructural encontrada al interior de las subregiones fue media-baja; sin embargo, al analizar todo el ACC, la homogeneidad y la armonía morfoestructural fue media-alta. Los índices etnológicos clasifican al ACC como longilíneo, hipermétrico, dolicocéfalo y concavilíneo, mientras que los índices productivos indican de un asno proporcionado, de buenos aplomos y de aptitud al trabajo.

No Morphological Integration of Dorsal Profiles in the Araucanian Horse (Colombia).

The aim of this research was to determine if the division between the cervical, dorsal, and croup profiles (three regions commonly assessed for descriptive profile purposes) has a modular basis as well as a morphological integration. For this, a total of 135 digital photographs were obtained, in a lateral view, of adult horses (14 females and 121 geldings; age range: 2-20 years), of the Araucanian breed, an equine population typical of the flooded savannah of Arauca, NE Colombia. From each image, 25 reference points (semi-landmarks) were obtained at the dorsal level of the neck, back, and croup. The hypothesis of the modularity of different body profiles based on differentiated regions was tested using the RV coefficient, and an analysis of two blocks of partial least-squares allowed the evaluation of the level of morphological integration. The results showed that each alloidic group reflected high integration but low modularity. The covariation between the modules was centered mainly on the withers, the loin, and the croup. For the studied profile blocks, no module can be considered. The absence of the fragmentation of the alloidic sets would promote the adaptive capacity of the breed by linking coordinated functional responses to similar selection pressures, e.g., field work. Although the integration between the neck, back, and croup profiles was proven, their modular covariation was low.

Descripción Anatómica de Bradypus variegatus en la Amazonia Colombiana (Estudio Preliminar) / Anatomical Description of Bradypus variegatus in the Colombian Amazonia (Preliminary Study)

En la Universidad de la Amazonia, en Florencia, Caquetá - Colombia, se llevó a cabo la descripción anatómica detallada del espécimen adulto de la especie Bradypus variegatus, a través de la cual se abordan aspectos clave de la osamenta, correspondientes al esqueleto apendicular, conformado por los huesos del miembro torácico (escápula, húmero, radio, ulna, carpos, metacarpos y falanges) y pelviano (pelvis, sacro, fémur, rótula, tibia, peroné, tarso, metatarso y falanges). Asimismo, se describe el esqueleto axial que corresponde a la línea media del esqueleto, formando el eje del cuerpo a través de los huesos del cráneo, columna vertebral, costillas y esternón. La descripción se desarrolló teniendo en cuenta metodologías previas y considerando datos de descripciones anteriores llevadas a cabo por otros autores, en algunas estructuras. Los resultados se consideran un precepto en el conocimiento del área quirúrgica como pieza fundamental en el desarrollo de la veterinaria en especies de fauna silvestre.

At the University of Amazonia, in Florencia, Caqueta - Colombia, a detailed osteological description of adult specimen of the species brown-throated sloth developed or Bradypus variegatus, through which key skeleton aspects are addressed, for the skeleton apendicular, comprising the forelimb bones (scapula, humerus, radius, ulna, carpal bones, metacarpals and phalanges) and pelvic (pelvis, sacrum, femur, patella, tibia, fibula, tarsus, metatarsus and phalanges). Also, the axial skeleton corresponding to the middle line of the skeleton, forming the body axis through the skull bones, spine, ribs and sternum described. The description was developed considering previous methodologies and data considering previous descriptions carried out by other authors in some structures. The results are considered a precept knowledge of the surgical area as a cornerstone in the development of veterinary species of wildlife.

The Stomach of the Adult African Catfish (Clarias gariepinus, Siluriforme s: Clariidae) in Farm Conditions: A Morphological and Mucin Histochem istry Analysis / El Estómago del Bagre Africano Adulto (Clarias gariepinus, Siluriformes: Clariidae) en Condiciones de Granja: Análisis Morforlógico e Histoquímico por Mucina

The stomach of the farmed African catfish (Clarias gariepinus, Siluriformes: clariidae) was investigated in this study to establish its basic anatomy, as there is scanty information available on the literature. It produced to baseline data for further investigative research, help fish clinicians in pathology and aid nutritionists in feed management. After cropping from a commercial aquaculture, apparently healthy fish were immobilized and euthanized by using chloroform. The samples were dissected and slices of cardiac, fundic and pyloric stomach processed through routine histological procedures. Grossly, the stomach was J-shape. Cranial to the stomach was the oesophagus but no sphincter was seen separating them. Caudally, a pyloric sphincter separated the stomach from the proximal intestine. The stomach contained three regions cardiac, fundic and pyloric. The entire stomach surface was lined by a simple columnar epithelium containing mucin at the apical cytoplasm. Only the cardiac and fundic regions contained gastric glands in the lamina propria, but the glands were more developed in the fundic region. The tunica muscularis contained smooth muscle cells in an inner circular and outer longitudinal orientation. Mucin histochemistry revealed the presence of only neutral mucin in the stomach. The results obtained in this study suggest that the absence of gastric glands in the pylorus may be an adaptation of this species to reduce the quantity of acid entering the proximal intestine; hence it might help the alkaline medium to maximize pancreatic enzyme actions in the proximal intestine. The presence of only neutral mucin in the stomach will act as a buffer to neutralize the high acidic stomach content. Neutral mucins are also associated with transport of macromolecules.

Se efectuó un estudio de tipo histológico e histoquímico con mucina, en el estómago del bagre africano (Clarias gariepinus, Siluriformes: clariidae) cultivado en granja acuícola, para establecer su anatomía básica, debido a la escasa información disponible en la literatura. La investigación generó datos para ulteriores investigaciones, que contribuirán con los ictiopatólogos y ayudarán a los nutricionistas en el manejo alimentario. Después de su cultivo en una granja acuícola comercial, los peces aparentemente sanos, fueron inmovilizados y sacrificados, usando cloroformo. Se tomaron muestras de las regiones cardial, fúndica y pilórica, y se procesaron histológicamente. En su conjunto, el estómago presentaba una apariencia de “J”. El esófago estaba situado cranealmente al estómago, pero no se observó un esfínter que los separara. Caudalmente, un esfínter pilórico separaba al estómago del intestino proximal. El estómago contenía tres regiones: cardiaca, fúndica y pilórica. La totalidad de la superficie estomacal se encontraba recubierta por un epitelio cilíndrico, que contenía mucina en el citoplasma apical. Solamente las regiones cardiaca y fúndica tenían glándulas gástricas en la lámina propia, que eran más desarrolladas en la región fúndica. La túnica muscular poseía células musculares lisas con una orientación interna circular y externa longitudinal. La histoquímica mediante la mucina reveló la presencia solo de mucina neutra en el estómago. Los resultados obtenidos en este estudio sugieren que la ausencia de glándulas gástricas en el píloro, pudiera ser el resultado de una adaptación de esta especie para reducir la cantidad de ácido que penetra en el intestino proximal; por tanto, pudiera ayudar al medio alcalino a maximizar las acciones de las enzimas pancreáticas en el intestino proximal. La sola presencia de mucina neutra en el estómago actuaría como amortiguador contra el elevado contenido ácido del estómago. Las mucinas neutras también están asociadas con el transporte de micromoléculas.

Caracterización morfológica e histoquímica del hígado de la baba (Caiman Crocodilus Crocodilus) / Morphological and Histochemical Characterization of the Liver of the Spectacled Cayman (Caiman crocodilus crocodilus)

La morfología, organización y los componentes intracitoplasmáticos del hepatocito de la baba (Caiman crocodilus crocodilus) son aspectos que se han estudiado parcialmente hasta el momento. Con el fin de generar información sobre la morfología microscópica del hígado de esta subespecie, se realizó un estudio descriptivo de las características morfológicas e histoquímicas del hígado de la baba, lo que permitirá la comprensión de algunas funciones hepáticas en estos ejemplares. De esta manera, se podrán realizar en el futuro, investigaciones utilizando a dicho órgano como modelo experimental para el estudio de las rutas metabólicas de los metabolitos procesados a este nivel. Se tomaron ocho muestras de hígado, se fijaron en formol al 10%  y se procesaron por los métodos histológicos de coloraciones de rutina (Hematoxilina y Eosina). Asimismo, se utilizaron las coloraciones especiales de Tricrómico de Gallegos, el método de Wilder y el aceite rojo “O”. Los hallazgos del presente trabajo revelaron la presencia de un hígado bilobulado, ubicado en la cavidad celómica caudal, con los  lóbulos derecho e izquierdo unidos por un istmo. El órgano se encuentra rodeado por una delgada cápsula de tejido conectivo, su parénquima se dispone en cordones tortuosos con un patrón acinar, con presencia de células pigmentadas compatibles con melanóforos, dispersas en el tejido hepático, y con gotas lipídicas intracitoplasmáticas de diversos tamaños, que en algunos casos ocupaban casi la totalidad del citoplasma de los hepatocitos.

The morphology, organization and intracytoplasmic components of the liver of the spectacled cayman (Caiman crocodilus crocodilus) are aspects that have been partially studied so far. A descriptive study of the morphological and histochemical characteristics of the liver of this subspecies was performed. This investigation would enable researchers to understand the liver functions in these animals, thus allowing future research using this organ as an experimental model. Eight liver samples were fixed in 10% v/v formalin and processed by conventional histology using routine hematoxylin and eosin staining. Additionaly, special stains, such as the Trichrome of Gallegos method and the red oil “O” and Wilder, were also used. The findings revealed the presence of a bilobed liver located in the midline of the caudal coelomic cavity, surrounded by a thin capsule of connective tissue; the parenchyma showed the layout of the classic hepatic lobule, the hepatocytes were arranged in tortuous cords and an acinar pattern. The presence of pigment-laden cells compatible with melanophores scattered in liver tissue was evidenced. Intracytoplasmic lipid droplets of various sizes occupying almost the entire cytoplasm of the hepatocytes were observed.

Concentración y morfología de los espermatozoides epididimarios obtenidos de toros postmortem / Concentration and Morphology of the Epididymal Spermatozoa from Post Mortem Bulls

Con el objetivo de evaluar la concentración y la morfología de los espermatozoides de la cola del epidídimo de testículos de toros postmortem, obtenidos mediante lavado por flujo retrógrado, se recolectaron al azar 90 testículos, los cuales fueron transportados bajo dos diferentes temperaturas, siguiendo dos protocolos diferentes: Protocolo 1 (35ºC) y Protocolo 2 (25ºC), durante el período abril-julio 2003. El material experimental fue transportado desde el sitio de la recolección hasta el laboratorio, en un lapso comprendido entre 30 y 60 min con un promedio de 45 min. Se realizó histopatología para seleccionar los testículos con 70% o más de tejido funcional para cada protocolo (Protocolo 1: n=13; y Protocolo 2: n=20). Una vez realizado el descarte de aquellos testículos que no cumplieron con esa premisa, se evaluó la concentración espermática y la morfología de los espermatozoides de las colas epididimarias en los testículos seleccionados. La recolección de esos espermatozoides se realizó por lavado retrógrado con TRIS-yema-glicerol, a través del conducto deferente. Se determinó la concentración espermática mediante la cámara de Neubauer, en el fluido espermático y la morfología espermática se determinó en función del porcentaje de espermatozoides normales y de las atipias encontradas, previa tinción con Hema III. Los datos se analizaron mediante estadística descriptiva, y se realizó una prueba de t de Student para comparar muestras independientes. Los resultados obtenidos indican que no hubo diferencia significativas, entre los dos protocolos en la morfología normal, ni el total de atipias. Según este estudio, la temperatura de transporte no afecta la calidad espermática epididimaria.

In this investigation, the concentration and morphology of spermatozoa of the epididymal tail of post mortem bull testicles, obtained by retrograde flushing, were evaluated. The experiment was done from April-June 2003. Ninety testicles were randomly collected and transported to the laboratory, following two different temperature protocols: Protocol 1 (35°C) and Protocol 2 ( 25°C). The testicles were transported from the slaughterhouse (Frogorífico Industrial de Turmero, the State of Aragua, Venezuela) to the laboratory within a time frame of 30-60 min, with an average time of 45 min. For each protocol (Protocol 1, n=13; Protocol 2, n=20), a histopathological study of all samples was performed and those testes with 70% or more of functional tissue were selected. After discarding the testicles which did not comply with the required conditions, the spermatic concentration and morphology of spermatozoa were assessed. Spermatozoa collection was carried out by retrograde flushing using TRIS-egg yolk glycerol medium through the deferent duct. The spermatic concentration was obtained using the Neubauer chamber while the spermatic morphology was estimated by observation of smears stained with Hema III, and comparing the percentage of normal versus abnormal spermatozoa. The data was analyzed by descriptive statistics and the t test was applied to compare two independent samples. The results obtained showed no statistical significant differences between the two protocols, regarding normal morphology and total percentage of abnormal spermatozoa. It is concluded that the two different temperature protocols do not affect the quality of spermatozoa of the epididymal tail.

TOPOGRAPHY AND VISCERAL MORPHOLOGY OF THE Melopsittacus undulatus, SHAW 1805 / TOPOGRAFIA E MORFOLOGIA DAS VÍSCERAS DO PERIQUITO-AUSTRALIANO (Melopsittacus undulatus, SHAW 1805)

The aim of this research was to study the topography and morphology of Australian parakeet (Melopsittacus undulatus) viscera. Ten Australian parakeet were used (5 males and 5 females). The animals were fixed in 10% formaldehyde solution, through perfusion in the musculature and visceral cavity. Macroscopically, the Australian parakeet viscera did not show expressive differences when compared to other domestic birds species. Microscopically, the main difference was the presence of mechanoreceptors (Corpuscles of Pacini) in the tongue, found for the first time in this psittaciform  species.KEY WORDS: Melopsittacus undulatus, morphology, topography, viscera.

Em virtude da escassez de dados referentes à morfologia e topografia das aves em geral, o presente estudo teve como objetivo descrever a topografia e morfologia das vísceras do periquito-australiano (Melopsittacus undulatus), para assim proporcionar um conhecimento mais amplo sobre características específicas dessa espécie. Para a descrição da morfologia e topografia das vísceras foram utilizados dez periquitos, sendo cinco machos e cinco fêmeas. Os animais foram fixados com solução de formaldeído 10%, através de perfusão na musculatura e cavidade visceral. Macroscopicamente, as vísceras do periquito não apresentaram muitas diferenças comparadas a outras espécies de aves domésticas. Microscopicamente, a principal diferença estava na presença de mecanorreceptores (corpúsculos de Pacini) na língua, encontrados pela primeira vez nesta espécie de psitaciforme. PALAVRAS-CHAVES: Melopsittacus undulatus, morfologia, topografia, vísceras.

SCANNING ELECTRON MICROSCOPIC INVESTIGATION OF DENTINAL TUBULES IN MONKEY DENTIN / SCANNING ELECTRON MICROSCOPIC INVESTIGATION OF DENTINAL TUBULES IN Cebus apella DENTIN

The aim of the study was to investigate the number and diameter of the Cebus apella dentinal tubules. The roots of the Cebus apella teeth were examined in specific tooth locations: the apical, middle and cervical dentin. The calculations were based on the scanning electron microscope photographs of the fractured surfaces. The results showed that the average number of dentinal tubules for each location was: 74,800 tubules/mm2 for apical root dentin, 90,000 tubules/mm2 for mid-root dentin, 91,600 tubules/mm2 for cervical root dentin. The average diameter was the following: apical root dentin, 4,30µm; mid-root dentin, 4,37µm; cervical root dentin,  5,23µm. These findings demonstrate that the Cebus apella teeth are a suitable substitute for human in endodontics studies. KEY WORDS: Dentin, dentinal tubules, teeth.

The aim of the study was to investigate the number and diameter of the Cebus apella dentinal tubules. The roots of the Cebus apella teeth were examined in specific tooth locations: the apical, middle and cervical dentin. The calculations were based on the scanning electron microscope photographs of the fractured surfaces. The results showed that the average number of dentinal tubules for each location was: 74,800 tubules/mm2 for apical root dentin, 90,000 tubules/mm2 for mid-root dentin, 91,600 tubules/mm2 for cervical root dentin. The average diameter was the following: apical root dentin, 4,30µm; mid-root dentin, 4,37µm; cervical root dentin,  5,23µm. These findings demonstrate that the Cebus apella teeth are a suitable substitute for human in endodontics studies. KEY WORDS: Dentin, dentinal tubules, teeth.

SCANNING ELECTRON MICROSCOPIC INVESTIGATION OF DENTINAL TUBULES IN Cebus apella DENTIN / Scanning electron microscopic investigation of dentinal tubules in monkey dentin

The aim of the study was to investigate the number and diameter of the Cebus apella dentinal tubules. The roots of the Cebus apella teeth were examined in specific tooth locations: the apical, middle and cervical dentin. The calculations were based on the scanning electron microscope photographs of the fractured surfaces. The results showed that the average number of dentinal tubules for each location was: 74,800 tubules/mm2 for apical root dentin, 90,000 tubules/mm2 for mid-root dentin, 91,600 tubules/mm2 for cervical root dentin. The average diameter was the following: apical root dentin, 4,30µm; mid-root dentin, 4,37µm; cervical root dentin,  5,23µm. These findings demonstrate that the Cebus apella teeth are a suitable substitute for human in endodontics studies. KEY WORDS: Dentin, dentinal tubules, teeth.

The aim of the study was to investigate the number and diameter of the Cebus apella dentinal tubules. The roots of the Cebus apella teeth were examined in specific tooth locations: the apical, middle and cervical dentin. The calculations were based on the scanning electron microscope photographs of the fractured surfaces. The results showed that the average number of dentinal tubules for each location was: 74,800 tubules/mm2 for apical root dentin, 90,000 tubules/mm2 for mid-root dentin, 91,600 tubules/mm2 for cervical root dentin. The average diameter was the following: apical root dentin, 4,30µm; mid-root dentin, 4,37µm; cervical root dentin,  5,23µm. These findings demonstrate that the Cebus apella teeth are a suitable substitute for human in endodontics studies. KEY WORDS: Dentin, dentinal tubules, teeth.

TOPOGRAPHY AND VISCERAL MORPHOLOGY OF THE Melopsittacus undulatus, SHAW 1805 / TOPOGRAFIA E MORFOLOGIA DAS VÍSCERAS DO PERIQUITO-AUSTRALIANO (Melopsittacus undulatus, SHAW 1805)

The aim of this research was to study the topography and morphology of Australian parakeet (Melopsittacus undulatus) viscera. Ten Australian parakeet were used (5 males and 5 females). The animals were fixed in 10% formaldehyde solution, through perfusion in the musculature and visceral cavity. Macroscopically, the Australian parakeet viscera did not show expressive differences when compared to other domestic birds species. Microscopically, the main difference was the presence of mechanoreceptors (Corpuscles of Pacini) in the tongue, found for the first time in this psittaciform  species.KEY WORDS: Melopsittacus undulatus, morphology, topography, viscera.

Em virtude da escassez de dados referentes à morfologia e topografia das aves em geral, o presente estudo teve como objetivo descrever a topografia e morfologia das vísceras do periquito-australiano (Melopsittacus undulatus), para assim proporcionar um conhecimento mais amplo sobre características específicas dessa espécie. Para a descrição da morfologia e topografia das vísceras foram utilizados dez periquitos, sendo cinco machos e cinco fêmeas. Os animais foram fixados com solução de formaldeído 10%, através de perfusão na musculatura e cavidade visceral. Macroscopicamente, as vísceras do periquito não apresentaram muitas diferenças comparadas a outras espécies de aves domésticas. Microscopicamente, a principal diferença estava na presença de mecanorreceptores (corpúsculos de Pacini) na língua, encontrados pela primeira vez nesta espécie de psitaciforme. PALAVRAS-CHAVES: Melopsittacus undulatus, morfologia, topografia, vísceras.

Morfologia da glândula pineal de gambás (Didelphis sp) / Morphology of the pineal gland in opossum (Didelphis sp)

A glândula pineal deve ser analisada e estudada em animais da fauna brasileira, para que dados da pesquisa básica possam ser aplicados em novas técnicas de manejo reprodutivo destes animais, inclusive em cativeiro, face à íntima relação deste órgão fotorreceptor com o ciclo reprodutivo. Para este estudo, foram utilizados 10 gambás (Didelphis sp), provenientes do Departamento de Anatomia da USP e da UNIFEOB, já mortos e fixados. Nenhum animal foi submetido a situações de dor/sofrimento e ao sacrifício de sua vida. A glândula pineal foi encontrada em todos animais estudados e apresentou-se com diminutas dimensões, não sendo possível, portanto descrever-lhe características macroscópicas. Através da análise microscópica pudemos localizar a glândula no espaço correspondente ao plano mediano, em relação ao encéfalo, rostral e dorsalmente aos colículos rostrais, ventralmente aos hemisférios cerebrais e caudalmente à comissura habenular. Consiste de uma evaginação do teto do diencéfalo e mostra-se em forma de “U” invertido. Comparativamente a características de glândulas pineais de outras espécies animais, a do Didelphis genus, que estudamos, revela peculiaridades tanto em relação ao seu tamanho, apenas perceptível microscopicamente, quanto ao fato de apresentar células semelhantes às secretoras, dispersas também em áreas vizinhas. Tais peculiaridades motivam reflexões sobre o papel funcional da glândula, na espécie considerada.(AU)

The pineal gland must to be analyzed and studied in animals of the Brazilian fauna, to apply the data obtained in the basic research of new techniques at reproductive handling of these animals, including in captivity, in view of the close relation between this photoreceptor organ with the circadian and reproductive cycle. For this study, 10 opossums (Didelphis sp), had been used, already died and fixed, proceeding from the Department of Anatomy of USP and UNIFEOB. None animals were submitted to pain/suffering situations and their no life sacrifice. The pineal gland was found in all studied animals with and smaller dimention, not possessing, therefore goss features. By microscopy analysis we could found the gland in the correspondent space to median plan in relation to the encephalon, rostral and dorsally to the rostral coliculli, ventrally to the brain hemispheres and caudally to the habenular comissure. That consistes like an evagination of the diencephalons tectum showing the “U” shape. Considering other pineal glands and its features in different species, we note the gland is extremely small for it specie, possessing dispersed secretory cells in the nervous parenchyma whose form, sufficiently irregular, suggests a small hormonal performance to them in the Didelphis genus. Comparativelly of the pineal gland feactures in different animals, the Didelphis genus, that was our aim, shows pecualirity as in size relation, only microscopically visible, than the fact to prossessing similar secretory cells also dispased in neighbor areas. All pecualiarites suggest refletion about the function action of the gland at the studied specie.(AU)