574 



CELL DIVISION IN EGGS OF CREPIDULA. 



X. Effects of Hypertonic Sea Wateb— (Continued.) 

 1. NaCl Added to Sea Water. 



No. 



Stage. 



Per 



Cent. 



Time in 



Eesults. 















Solution. 



Normal S. W. 





970 



4-12 cells. 



2 



16hrs. 



Ohrs. 



4-12 cells; similar to preceding, but modifications more 



pronounced. 

 4-12 cells; great numbers of karyomeres and con- 



971 



4-12 cells. 



2 



16hrs. 



12 hrs. 













stricted nuclei, polyasters. 



972 



4-12 cells. 



2 



16hrs. 



24 hrs. 



4-20 cells; very abnormal cleavage; yolk cleavage some- 

 times suppressed, sometimes increased; many poly- 

 asters and karyomeres. Figs. 220, 223. 



973 



2-20 cells. 



3 



lhr. 



lhr. 



2-20 cells; nearly normal; few cells show any signs of 



plasmolysis. 

 24-44 cells; mostly normal; in a few eggs yolk cleavage 



974 



2-20 cells. 



3 



lhr. 



16 hrs. 













suppressed, polyasters and karyomeres. 



975 



2-20 cells. 



3 



lhr. 



24 hrs. 



30-52 cells; similar to preceding. 



976 



2-20 cells. 



3 



lhr. 



39 hrs. 



60-70 cells; almost all normal; a few karyomeres. 



977 



2-20 ceUs. 



4 



lhr. 



lhr. 



2-20 cells; plasma, nuclei, spindles are normal; have 

 recovered from plasmolysis. 



978 



2-20 cells. 



4 



lhr. 



16 hrs. 



20-50 cells; plasma, nuclei and spindle normal. 



979 



2-20 ceUs. 



4 



lhr. 



24 hrs. 



20-60 cells; chiefly normal; a few karyomeres. 



980 



2-20 cells. 



4 



lhr. 



39 hrs. 



60-70 cells; chiefly normal; a few degenerating mitotic 

 figures which never recovered; few karyomeres. 



981 



1-20 cells. 



5 



|hr. 



2 hrs. 



1-20 cells; chiefly normal; few signs of plasmolysis; a few 

 chromatic connections between daughter nuclei. 



982 



1-20 cells. 



5 



f*hr. 

 1* hr. 



18 hrs. 



24-44 cells; chiefly normal; no polyasters or karyo- 











meres. 



983 



1-20 cells. 



5 



lhr. 



24 hrs. 



2-52 cells; mainly normal; some earlier stages ab- 

 normal, with suppressed or increased yolk cleavage, 

 polyasters and karyomeres. 



984 



1-20 cells. 



5 



fhr. 



40 hrs. 



60-70 cells, mainly normal; a few abnormalities of earlier 

 stages similar to preceding. 



985 



2-20 cells. 



6 



fhr. 



2 hrs. 



8-24 cells, mainly normal; plasma, nuclei, spheres, 

 spindles show no trace of plasmolysis. 



986 



2-20 cells. 



6 



fihr. 

 1 fhr. 



18 hrs. 



2-40 cells, mainly normal; some early stages show 











suppression of yolk cleavage, with polyasters and 













karyomeres; later stages are normal. 



987 



lcell. 



6 



thr. 



24 hrs. 



1-4 cells; suppressed cleavage, polyasters, karyo- 



988 (1) 



1-4 cells. 



1 



2hrs. 



Ohrs. 



meres. 

 1-4 cells; no cleavage; nuclei and spindles shrunken; 

 achromatin withdrawn from radiations into spindle, 

 leaving isolated portions of achromatin, which 

 become cytasters. 



(2) 



1-4 cells. 



1 



4hrs. 



Ohrs. 



1-4 cells; similar to preceding. 



(3) 



1-4 cells. 



1 



5 hrs. 



Ohrs. 



1-4 cells; similar to preceding. 



989 (1) 



lcell. 2d 



Maturation 



1 



4f hrs. 



Ohrs. 



1 cell; nuclei and spindles slirunken; cytasters. 



(2) 



1-4 cells. 



1 



4fhrs. 



Ohrs. 



1-4 cells; plasma, nuclei and spindles shrunken; few, if 



any, cytasters. 

 1-16 cells; suppressed and unequal cleavage of yolk; 



(3) 



1-4 cells. 



1 



4f hrs. 



13 hrs. 













polyasters, karyomeres; enormous asters surrounded 

 by many chromosomes. 













990 (1) 



1-4 cells. 



4 



2f hrs. 



13* hrs. 



2-16 cells; scattered chromosomes; chromatic con- 

 nections between daughter nuclei; polyasters, karyo- 

 meres, big nuclei and nucleoli. 



(2) 



1-4 cells. 



1 



2f hrs. 



13Jhrs. 



24-44 cells; increased cleavage of yolk. 



(3) 



1-4 cells. 



4 



2|hrs. 



24 hrs. 



1-24 cells; yolk cleavage may be suppressed in 1st and 

 2d cleavages, increased in later cleavages; polyasters, 

 karyomeres; no normal mitoses. 



(4) 



1-4 cells. 



1 



2f hrs. 



24 hrs. 



52-60 cells; mostly normal. 



(5) 



1-4 cells. 



1 



2f hrs. 



36 hrs. 



68-76 cells; a few karyomeres and polyasters. 



