Abstract
Nucleolar number per nucleus was observed on nuclei isolated from various kinds of organs in rodents. The nuclear isolation was carried out by the technique of DOUNCE with some modifications. Identification of nucleoli based on the previous work of the author. This observation was attained to acertain differences of the mean nucleolar number per nucleus between organs, between animals or sexes (See Table 1). The data obtained are as follows (See Tables 2-5):
The mean number of nucleoli observed on a certain organ is mostly constant among animals of the same species, and the coincidence of this mean seems not greatly affected with body weight of the animal. Marked differences are, however, often found between different organs of the same animal. The mean observed on a certain organ is varied by difference of the animal species, but it is mostly well agreeable between livers of rat and guinea pig, in which any difference of the mean can not be demonstrated between both sexes.
From these findings a concept of constancy of the nucleolar number does not fit for each somatic nucleus in rodents, but it might be assumed that some properties of the organ were represented partly in the mean number of nucleoli and lesser in the nucleolus of each nucleus.
