PLATE LVIII. 

 Effects of Hypertonic Sea Water. 



All eggs represented on this plate were put into hypertonic solutions in the 1-cell stage, and with the 

 exception of fig. 197 none of them show division of the yolk. 



Fig. 197. Exp. 842: 4 per cent. MgCl 2 , 5 hrs., normal 17 hrs.; the two cells at the upper pole are 

 probably enormous polar bodies, both of which contain mitotic figures. 



Fig. 198. Exp. 991: 1 per cent. MgCl 2 , 18 hrs.; one large cell (macromere) contains all the yolk, two 

 smaller cells (micromeres) are purely protoplasmic; both macromeres and micromeres contain many nuclei 

 (karyomeres), the chromatin of each being condensed into one or two masses. 



Fig. 199. Exp. 834: 3 per cent. MgCl 2 , 9 hrs., normal 9 hrs.; both macromere and micromere contain 

 mitotic figures with many poles and scattered chromosomes; sphere granules at the animal pole of the 

 micromere. 



Fig. 200. Exp. 833: 2 per cent. MgCl 2 , 9 hrs., normal 9 hrs.; resting stage following a division stage 

 like that of the preceding figure. 



Fig. 201. Exp. 838: Herbst's Ca-free sea water, 18 hrs.; micromere and macromere containing 

 many nuclei and cytasters. 



Fig. 202. Exp. 825: 2 per cent. NaCl, 16 hrs., normal 23 hrs.; two spheres and many scattered nuclei 

 (karyomeres) in both macromere and micromere. 



Fig. 203. Exp. 827: f per cent. NaCl, 9 hrs., normal 8 hrs.; many asters and scattered chromosomes 

 in the macromere and in one of the micromeres. 



Fig. 204. Exp. 863: 2 per cent. NaCl, 2 J hrs., normal 10 hrs.; similar to the preceding; scattered 

 spindles and chromosomes; three small micromeres (lobes) budding off from the macromere; sphere granules 

 at the animal pole of the micromeres. 



Fig. 205. Exp. 843: 1 per cent. NaCl, 6 hrs., normal 15 hrs.; several micromeres, three of them 

 containing several nuclei or groups of chromosomes; the macromere contains many nuclei (karyomeres). 



Fig. 206. Exp. 827: § per cent. NaCl, 9 hrs., normal 8 hrs.; macromere and micromeres containing 

 many karyomeres and asters. 



Fig. 207. Exp. 830: 2 per cent. NaCl, 9 hrs., normal 32 hrs.; macromeres and micromeres containing 

 a large number of karyomeres or asters; sphere granules under the polar body. 



Fig. 208. Exp. 833: 2 per cent. MgCl 2 , 9 hrs., normal 9 hrs.; many nuclei (karyomeres) and spheres 

 in each cell. 



