Experimental Studies on Germinal Localization. 51 



Fragments of fertilised Eggs, horizontal Section; isolated Polar Lob'es and/ 



Fragments of Lobes. 



94, 95, Equal twins from the same egg ; 9Sa, 95b, upper half, 2- and 8-cell 

 stages ; 943-941, successive changes in the lower enucleated fragment ; 94a, soon 

 after operation; 94b, first polar lobe (drawn immediately before 9Sa) ; 94c, first 

 resting stage, upper fragment in 2-cell stage (23 m. after b) ; 94d, second polar 

 lobe (21 m. after c, the upper fragment just divided into 4) ; 94e, second rest 

 (16 m. after d) ; 94f, third polar lobe (i6m. after last, at nearly .the same time 

 with 9Sb) ; 94g, third rest (7 m. after last) ; 94h, fourth lobe (46 m after last, 

 fourth cleavage in progress in upper fragment) ; after 16 minutes the' fragment 

 appeared to be divided into two and so remained ; 94i, the same four hours 

 later; 96, lower fragment, like last, but showing correct proportions of first 

 polar lobe; 97, successive changes in isolated polar lobe from the individual 

 shown in Fig. 21; 97a, soon after removal; 97b, first active period (16 m., the 

 egg just divided into 4) ; 97c, ensuing first resting period (14m. after b) ; in the 

 second period of activity (not sketched), 15 m. later, as the eggs divided into 

 8, the lobe constricted as in b, but not so deeply, and again became spherical in 

 a second resting period ; 97d, e, third period of activity, 74 and 78 ni. after the 

 first period; 97f, final result, 36 m. later; 98, another isolated lobe, 98a, third 

 resting period; 98b, second lobe; 98c, final result, in which condition it re- 

 mained without further change; 99, 100, two fragments obtained by cutting 

 a polar lobe in two (the original lobe was slightly larger than usual), showing 

 active changes shortly after division of the egg into 4; 99a, looa, are shown 

 42 m. after 99 and 100; 99b, loob, 8 m. later; 99 remained in this condition, 

 while 100 again became spherical by fusion of the two halves and underwent 

 no further change. 



