EFFECTS OF AGING UPON GERM CELLS. 375 



Female i, is an example of the first group. When her eggs 

 were 5 hours old, i. e., 5 hours after liberation, their diameters 

 were 19 and 19.5 units. When her eggs were 22 hours old, they 

 measured 20, 20.5 and 21 units, a dear and sharp -increase in 

 minimum, mode and maximum diameters, with age. 



In female 2, observations were made when the eggs were 5 and 

 29 hours old. In this female there was also an enlargement but 

 very small. In females 3 and 4, observations were made at Y% 

 and 1 8 hours respectively. In each female the eggs enlarged 

 with age. In female 5, three observations were made, viz., 2, 5 

 and 24 hours, with a progressive enlargement at each successive 

 age. In female 6, observations were made at four intervals, 

 3, 9, 27 and 33 hours. As in female 5, there was at first a rapid 

 enlargement of the eggs, then a slow increase, and, in very late 

 aging, a rapid increase again. The average diameters at each 

 of the four intervals was 19.44, 19-80, 19.77 an d 19.96. 



In all the eggs of this first group, there was a cumulative in- 

 crease in volume, with age, for the first 33 hours. 



The second group includes such females whose eggs were 

 observed over a longer period than 33 hours. In this group as in 

 the first, the eggs also enlarged at first, with age, but after a 

 longer interval there occurred a secondary diminution in size, 

 and in very old eggs became even smaller than the norm. 



For example, the eggs of female 7 were measured at O, 18, 24, 

 40 and 47 hours. When 18 hours old the eggs were slightly 

 larger than at the first observation. At 24 hours, the eggs were 

 clearly smaller, and at 40 hours smaller still. At 47 hours they 

 were much below their original size and below the norm for the 

 species. The maximum size had diminished from 20.5 to 18, 

 the mode from 19.5 to 17.5, the minimum from 19 to 17. 



In female 8, there was the same initial increase and subsequent 

 diminution towards the norm, when 24 hours old. In female 9, 

 observations were made at o, 18, 24, 40 and 47 hours. There 

 occurred the usual enlargement until the 4Oth hour, after which 

 there was a definite diminution in volume. 



In a third group, of a few females only, the eggs though 

 freshly removed, were in poor physiologic condition. In this 

 group the initial enlargement did not take place. In these eggs 



