Characteristics of the menstrual cycle in nonhuman primates. I. Similarities and dissimilarities between Macaca fascicularis and Macaca arctoides.

Comparative studies of reproductive characteristics were carried out on a colony of Macaca fascicularis and M. arctoides. Seasonal differences were not significant between species, and conceptions occurred throughout the year.

Collection of control data from teratological experiments on mice, rats, and rabbits. A group study.

A joint study was undertaken in the laboratories of five pharmaceutical companies to evaluate accumulated data on the progeny of mice, rats and rabbits of various strains or breeds. The recorded morphological deviations from normal were classified according to the time of their occurrence during embryonic and foetal development, and three categories were differentiated. Comparison of the data from the various laboratories in general revealed similar results, and the variations observed are presumed to be due to differences in experimental conditions.