AN EXTRA DYAD AND EXTRA TETRAD IN CAMNULA 387% 
individuals still to be considered. ‘The results of these counts in 
nos. 980, 2511, and’ 2525 are given in the form of tables. It is to 
be understood that, though the valence of the accessory is not 
given in the case of the first spermatocytes, it is always a dyad 
in this cell generation and passes to one of the poles undivided, 
as a V, during the anaphase. Where only two or three counts 
are given for a particular cyst, as is usually the case for the 
spermatogonia, it is to be understood, also, that it was not pos- 
sible to secure more of a trustworthy character. This was some- 
times the case (as in the spermatogonia), because the cyst 
contained but a few cells. First and second spermatocyte cysts 
often contain cells in different phases; hence, though there are 
sixty-four cells in the former and one hundred and twenty-eight 
in the latter, it is sometimes possible to make but two or three 
counts. 
In the tables the counts have been arranged like the counts 
just given for 950, by cyst and follicle. The cysts are numbered 
consecutively in the order in which they were examined. The 
follicles are denoted by letters and are represented by the hori- 
zontal columns. ‘The vertical columns represent the three classes 
of germ cells: spermatogonia, first spermatocytes, and second 
spermatocytes. Since the results of the counts in each cyst are 
placed in the proper columns horizontal and vertical, all the counts 
of a given cell generation or of a particular follicle may readily 
be compared. (Table 1, p. 389.) 
In individual 2526 (from San Juan Island, 1915) counts were 
obtained in eight spermatogonial cells from five cysts, one hun- 
dred and seventy-one first spermatocyte cells distributed among 
ten cysts, and forty-four second spermatocytes from eight cysts. 
These twenty-three cysts (all in which mitotic figures occur) are 
contained in twenty different follicles. The chromosome count is 
constant for these twenty follicles. The spermatogonial com- 
plexes consist of twenty-five dyads each, the first spermatocytes 
of twelve tetrads and one dyad (the accessory). Two classes of 
second spermatocytes were found, containing respectively twelve 
and thirteen dyads. Representative complexes of all three cell 
generations are illustrated on plates 13 and 14. 
