PLATE LVII. 



Effects of Hypertonic Sea Water. 



Figs. 183-185 were in 1-cell stage at beginning of experiment; Figs. 186-196 were in 2-cell stage. 



Fia. 183. Exp. 805: 2 per cent. NaCl, 4 hrs.; in both egg and sperm nuclei the chromatin is aggregated 

 into a dense mass in the center of the nuclear vesicle; there are many cytasters near the sperm nucleus. 



Fig. 184. Exp. 809: 2 per cent. NaCl, 15 hrs.; the chromatic and achromatic parts of the germ 

 nuclei are in separate vesicles. 



Fig. 185. Exp. 809: Similar to the preceding; a double cytaster is present near the germ nucleus. 



Fig. 186. Exp. 809: 2 per cent. NaCl, 15 hrs.; the chromatic and achromatic parts of the nucleus are 

 in separate vesicles; the achromatic vesicles are numerous and scattered. 



Fig. 187. Exp. 809: Side view of egg similar to preceding. 



Fig. 188. Exp. 809: Egg similar to the preceding showing two principal achromatic vesicles (Ach) 

 and many smaller vesicles or sphere granules. 



Figs. 189, 190. Exp. 805: 2 per cent. NaCl, 4 hrs.; the 2d cleavage spindles are much shrunken in 

 size; the archiplasm around them is much condensed while many small radiating masses of archiplasm 

 are left along the astral radiations as cytasters. 



Figs. 191, 192. Exp. 823: 3 per cent. NaCl, 16 hrs., normal 8 hrs.; top and side views of eggs showing 

 in addition to the principal masses of chromatin (Ch) very numerous granules or spherules which probably 

 represent scattered achromatic material (Ach). 



Figs. 193, 194. Exp. 837: 1 per cent. KC1, 9 hrs., normal 36 hrs.; the numerous karyomeres have 

 begun to absorb achromatin and to fuse together. 



Figs. 195, 196. Exp. 808: 1 per cent. NaCl, 15 hrs.; top and side views of eggs with two macromeres 

 and two micromeres, each with many masses of chromatin (karyomeres) and several spheres or asters. 



