(Continued from page 304) 



17a Nucleus with -i nuclooli, nine fat globules, mitochondria, vacuoles with 

 and without blue granules (black in figure). 



176 Contains two very large vacuoles with very large blue granules. 



18a-18e Five views of a group of five cells on the seventh day of cultivation, 

 explant from a ten day embryo; tryjjan blue in medium, supra-vitally stained in 

 neutral red. Showing degeneration by bleb formation. X 750. 



18a 12.45 P.M. Showing cell outlines, nuclei, fat globules, and angular rose- 

 red stained granules (black in figure). Spaces have developed between con- 

 tiguous cells, mitochondria not shown. 



186 1.25 P.M. The mitochondria and nucleoli are shown in this view in addi- 

 tion to the granules. Cell boundaries have disappeared, and bleb formation 

 has begun. 



18c 1.45 P.M. The blebs are much larger, and the mitochondria have lost 

 their clear cut outlines and have become indistinct granular bodies. The roser 

 granules are still well stained. 



18d 2.45 P.M. The rose color has disap]ieared from the granules leaving 

 them a bluish-gray color. Neutral red has been again added, but the granules 

 have not taken it up, retaining the bluish-gray color. The mitochondria have 

 become still more indistinct and the blebs have decreased in size and number. 



18e 3.45 P.M. Bleb formation has entirely disappeared and the cells are 

 merely accumulations of granular masses representing the mitochondria, with a 

 few darker bodies among them, the granules which still retain some of their 

 trypan-blue staining. 



PLATE 4 



EXPLANATION OF FIGURES 



19 and 20 From 6 day culture, explants from 8 day embryo. Liver cell mem- 

 brane and endothelial reticulum. Fixed in Schaudinn's fluid, iron haematoxj'lin. 

 X 125. 



306 



