244 
ZOOLOGY: A. J. GOLDFARB 
(d) The rate of early cleavage (first and second) and the total cleav- 
age showed even greater variations, from complete or almost complete 
sterility to 100%. High percent cleavage was correlated with little 
variation in size, globular shape, high percent jelly layer, and rapid 
membrane formation. The reverse conditions were associated with 
low ' cleavage. In these ways one may separate the so-called 'good^ 
from 'bad' eggs, which morphologically are indistinguishable. A single 
example of 'good' and 'bad' females are given below: 
SPECIES 
NUM- 
BER OF 
MALE 
NUMBER OF FEMALE 
MAXI- 
MUM 
DIFFER- 
ENCE 
TIME 
CON- 
STANT 
1 
2 
3 
4 
5 
6 
7 
Toxopneustes 
1 
99 
83 
98 
99 
16% 
2 hrs. 
2 
81 
76 
18 
14 
40 
72 
Hipponoe 
1 
92 
97 
83 
14 
2 
90 
54 
59 
47 
16 
74 
1 
100 
100 
0 
Arbacia 
2 
99 
98 
97 
97 
98 
99 
99 
7 
3 
81 
58 
1 
77 
91 
90 
The amazingly large variability in these fresh germ cells finds its 
explanation in the following facts: (1) There is a primary small vari- 
ation in fresh eggs of any female. (2) Eggs do not all ripen at the same 
time but at different intervals, within the body of the female. (3) 
Injurious changes occur in the eggs from the moment they ripen. (4) 
The time of elapsing between maturation and removal from the body 
niay be different for different females, and therefore the intensity of 
the changes will be different for different females. (5) Sea water is 
also slightly injurious to ripe eggs, and the already different physiologic 
condition of the eggs is further heightened by the differential effect of 
the sea water. 
Eggs removed from dift'erent females at the same time though of the 
same chronologic age are nevertheless rarely in the same physiologic 
condition. In order to determine their physiologic state and there- 
fore, in order to separate the eggs according to their physiologic condi- 
tion, it becomes necessary to ascertain in the manner just described 
the degree of variation of size, of jelly, and better still of membrane 
formation, and still better of cleavage, as well as by other means. 
It becomes highly probable in view of these facts that the varying 
behavior of the eggs in the experiments of J. Loeb, F. Lillie, R. Lillie, 
Wasteneys and others was due in large part to a variation in the physi- 
