394 



Table showing the number of sex-cells in embryos ranging in c — t 

 length from 5 mm to 8 mm. In nos. 15 and 16, the cells have not 

 yet reached their final positions. 



Int. = Intestine, whether open or closed. 



Mes. = Mesentery. 



E. Sex-gland = Eight Sex-gland. 



L. Sex-gland = Left Sex-gland. 



Ad. = General region of adrenal bodies as explained in text. 



**/„ = Percentage of sex-cells in the sex-glands as compared with the total number 



of the embryo. 



In the following embryos, sex-cells were counted only in one or 

 both of the sex-glands. The carapace measures are given. Number 

 33 c — t 8 has a carapace length of 5 mm. 



Number Carapace length E. Sex-gland 



34 

 35 

 36 

 37 

 38 

 39 

 40 

 41 



42 



6,0 mm 



6,0 



6,5 



7,0 



7,5 



7,5 



7,5 



8,0 



8,0 



156 



110 



508 Division figures found 



114 No division figures 



294 



239 



258 



205 Some in process of division 



L. Sex-gland 



jSl A few divi- 

 2ß9 ( siou figures 



192 Just begin- 

 ning to divide 



It will be noted that the total numbers in the early stages are 

 similar to the totals in the later stages. The average of the totals 

 of embryos 1 — 16 is 1122, while that of embryos 17 — 33 is 1052. 

 The slight difference might be accounted for by the fact that the total 

 numbers of sex-cells in embryos 18 — 21, all from the same nest, are 

 abnormally low. The fact that these numbers vary within about the 



