The influence of negative ionization of the air on motor activity in Syrian hamsters (Mesocricetus auratus Waterhouse) in light conditions.

The motor activity of Syrian hamsters (Mesocricetus auratus Waterhouse) under the influence of negative ionization of the atmosphere applied for 10, 20 or 30 min per day was investigated. An ionizer with output of 14,000 light negative ions per 1 cm3 of air was used. Studies carried out in the light phase of a 12:12 h light/dark regime revealed a relation between the reaction of the animal and the time of day at which ionization was applied. Ionization for 20 or 30 min in the light phase decreased motor activity, while 10 min of ionization increased it compared to control animals. Ionization in the dark phase gave a more distinct rise in activity than that applied in the light phase for all three durations of ionization.

Colour perception in cows.

Cows of the Lowland Black-and-White breed were studied by the method of discrimination conditioning according to the differentiation of seven colours in Oswald's scale (yellow no. 2, pink no. 5, red no. 7, violet no. 12, blue no. 15, green no. 21 and yellowish-green no. 23) from 16 shades of grey in Hering's scale. The high percentage of choices made leads to the conclusion that cows see colours as distinct entities. It was found from the percentage of positive reactions obtained to a given colour that a sequence exists in the cows' differentiation of colours. In connection with this the relativelability to distinguish the different colours listed above was established and estimated statistically (by t-test). Emphasis has also been laid on ethological variations with respect to differences in temperament and social status of the cows and the result of colour differentiation learning.