[Neuroendocrine control of reproduction in molluscs]. / Contrôle neuroendocrine de la reproduction chez les mollusques.

Experiments carried out, in vitro and in vivo on gastropods and lamellibranchs have shown the existence of gonadic factors of differenciation and working. In hermaphrodites or gonochoric molluscs, the primary germ cells self differentiate into oogonia and oocytes, the differenciation and maintenance of male cells depending upon factors secreted by the cephalic ganglia. Neurosecretory cells seem to exert a control upon mitosis of germ cells, meiosis, vitellogenesis (cerebral ganglia) or spawning (visceral ganglia). Some organs present in gastropods (dorsal bodies, optic tentacle) could act to modulate these actions.

[Solubility of the neurosecretory products of Crepidula fornicata Phil., a prosobranch mullusk]. / Solubilité des produits de neurosécrétion chez Crepidula fornicata Phil. Mollusque Prosobranche

Study of solubility of neurosecretory products in Crepidula fornicata shows that the presence of ethanol in the fixative is incompatible with good fixation. This character permits the choice of a more effective extraction technique. An experimental study in organ culture shows that the action of differentiation of brain appears in the extract obtained by this method.