578 



Gideon S. Dodds. 



The following table presents the results of these counts for 

 a number of individuals (these denoted by letters) of each stage: 



TABLE 1. 



Showing number of germ-cells 



A study of the above table shows, first of all, that while the. 

 number of germ-cells in all embryos is not the same, yet in stages 

 8-14 there is no general increase, the average number in stage 8 

 being the same as in stage 14. The number of embryos studied 

 is too small to allow us to determine with accuracy the general 

 average or the range of variation, but it is sufficient to show that 

 there is no increase in number during this period. That there is 

 no increase in number might be inferred from the absence of 

 mitoses in these cells during the same period. In stage 14, how- 

 ever, there are seen changes in the nuclei of the germ-cells which 

 indicate that they are in preparation for division, so that it is 

 very probable that in fish a little older the number would be 

 greater. Stage 14 may then be considered as, in all probability, 

 marking the close of the rest period of the germ-cells. 



The variation in the number of germ-cells in different embryos 

 is also very evident. In the fifteen embryos of stages 8-14 in 

 which careful counts were made, the extremes are 28 and 45, by 

 far too great a variation to be explained as inaccuracy of count. 

 This is not in accord with "the numerical law of germ-cells" 

 as expressed by Beard ('02 d), which demands that the number 

 during this period shall be the same in all individuals. 



