562 



CELL DIVISION IN EGGS OF CREPIDULA. 



III. Effects of Peessuhe. — (Continwd.) 



Experiment. 



Duration, 



Free 



in Sea 

 Water. 



910 

 911 

 912 

 913 



914 

 915 



916 

 917 

 918 



919 

 920 



1.000 (1) 

 (2) 

 (3) 



1.001 (1) 



(2) 

 (3) 



1.002 (1) 



(2) 

 1,003 



W S 



4-20 cells. 



lcell. 

 4-16 cells. 



1 cell. 



4-16 cells. 

 1 cell. 



4-8 cells. 



4-16 cells. 



lcell. 



lcell. 



4 cells. 

 1-2 cells. 

 1-2 cells. 

 1-2 cells. 

 1-2 cells. 



1-2 ceUs. 

 1-2 ceUs. 



1-2 ceUs. 



1-2 cells. 

 1-4 cells. 



1-2 ceUs. 

 1-2 cells. 



Pressed out of 

 capsules, 

 ressed out of 

 capsules. 



Pressed in cap- 

 sules. 



Pressed in cap- 

 sules. 



Pressed in cap- 

 sules. 



Pressed in cap- 

 sules. 



Pressed out of 

 capsules. 



Pressed in cap- 

 sules. 



Pressed out of 



Pressed out of 



capsules. 

 Pressed out of 



capsules. 

 Compressorium. 



Compressorium. 



Compressorium. 



Compressorium. 



Compressorium. 

 Compressorium. 



Pressed between 



Pressed between 



slides. 

 Pressed between 



slides. 



Compressorium. 

 Compressorium. 



4 hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



16 hrs. 



16 hrs. 



16 hrs. 



15 hrs. 



15 hrs. 

 15 hrs. 



5} hrs. 



5J hrs. 

 7 hrs. 



7Jhrs. 

 7} hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



4 hrs. 



6 hrs. 



6 hrs. 



6 hrs. 



6 hrs. 



6 hrs. 



6 hrs. 



6 hrs. 



hrs. 



6 hrs. 



16 hrs. 



hrs. 



5} hrs. 

 15* hrs. 



hrs. 



7 hrs. 

 hrs. 



hrs. 

 7 hrs. 



4-24 cells; many isolated macromeres. 



1-8 macromeres, which are abnormal in size 



and position. Figs. 51, 52, 53. 

 24-30 cells; normal. 



1—16 cells; cleavage of yolk suppressed in 

 some eggs, increased in others (1-many 

 macromeres), depending on axis of pressure. 



24-30 cells; few modifications. 



1-8 macromeres with corresponding micro- 

 meres; many exovates and lobes; amitosis- 

 like division figures. Figs. 54, 56, 59, 60, 

 61, 65. 



4-24 cells; a few exovates and isolated macro- 

 meres. 



24-30 cells; nearly normal. 



1-20 cells; many modifications in number, size 

 and position of macromeres. Figs. 45, 46, 

 58. 



Similar to preceding. Fig. 77. 



8-24 cells; similar to No. 918. 



16-25 cells; more than 4 macromeres with 

 corresponding micromeres. Fig. 62. 



16-30 cells; a few eggs with exovates and more 

 than 4 macromeres. Fig. 63. 



52-70 cells; some isolated macromeres, showing 

 partial cleavage. Fig. 67. 



1-24 cells; many isolated macromeres, also 

 eggs with 1-8 macromeres; exovates. , Fig. 

 66. 



1-42 cells; similar to preceding. 



52-70 cells; a few with more than 4 macro- 

 meres. Figs. 67, 76. 



1-8 cells; macromeres abnormal in number, 

 size, and position; exovate and isolated 

 macromeres. 



8-25 cells; similar to preceding. Fig. 42. 



2-16 cells; macromeres abnormal in number, 

 size and position; isolated macromeres and 

 and exovates. Figs. 57, 58. 



1-16 cells; similar to preceding. 



8-40 cells; similar to No. 1,002 (2). 



