GERM CELLS OF ANURANS 247 
and an irregular linin network upon which is scattered chromatin 
granules of various size and shape, together with one or more 
nucleoli. The nuclear size is in many instances enormous, com- 
pletely filling the cytoplasm except for a narrow peripheral border 
(figs. 1, 3, 115 and 117). 
The character of the attraction sphere and centrosome pre- 
sents nothing unusual and conforms to the type described for 
amphibians by earlier workers, hence it need not detain us here. 
Division of the primary spermatogonia is always mitotic, and 
amitosis, though described for this type of cell in amphibians by 
La Valette St. George ('85), Meves ('91), Benda ('93), and 
McGregor ('99), has not been observed in Rana catesbeiana. 
The somatic or diploid number of chromosomes in the male 
bullfrog larva is twenty-eight, and presumably this number is 
characteristic of the adult also, though no counts have been made 
on metamorphosed animals. A few years ago the writer found 
that twenty-six is the male diploid number for Rana pipiens, 
the leopard frog (Swingle, '17). Parmenter ('20) has recently 
confirmed this count for parthenogenetic frogs of the same species. 
According to King ('07), the somatic number in Bufo is twenty- 
four. This last number has also generally been regarded as charac- 
teristic for urodeles, such as Triton and Salamandra. Recently 
Snook and Long ('14) described twenty-eight chromosomes in 
the urodele Aneides lugubris, and Parmenter ('20) finds the same 
number in the larva of Ambystoma tigrinum. Levy ('14-'15) 
states that the diploid number in male Rana temporaria is twenty- 
five. The writer does not regard Levy's evidence as above crit- 
icism, and is much inclined to consider this statement as possibly 
a mistake. It would be odd if the males of all other amphibians, 
both urodeles and anurans so far studied, possessed an even num- 
ber of chromosomes, and one species, Rana temporaria, possessed 
an odd number. Levy regards this species as having an accessory 
chromosome. 
The writer described an odd chromosomal body in the germ 
cells of Rana pipiens as an accessory chromosome (Swingle, '17), 
but has since been in doubt in regard to this matter. The body 
described by me is probably a precociously dividing chromosome, 
