PLATE 2 



EXPLANATION OF FIGURES 



3a-3c Three views of the upper edge of the explant shown in figure la, 3a the 

 edge at 12.00 noon; 3b at 2.25 p.m. ; and 3c at 2.30 p.m. The outlines of the indi- 

 vidual liver cells, the nuclei, the fat globules, many free in medium, and one 

 clasmatocyte are shown. X 312. 



4o-4g Seventeen views of a group of liver cells along the edge of an explant 

 from an eight day embryo on the second day of cultivation. On the fourth day 

 of cultivation this plant had given rise to an excellent liver cell growth. X 312. 



4a 2.00 P.M. Showing the two cells (numbered 4 and 5) which had migrated 

 out from the explant at this point. 



4b 2.30 P.M. Showing the four additional cells which had grown out in the 

 intervening half hour. (Numbers 1, 2, 3, and 6.) 



4:C-4j. 2.40-3.55 p.m. Eight views drawn at ten minute intervals showing the 

 movements of these six cells. 



4/c 4.00 p.m. a seventh cell has grown out. 



4il^q 4.15-4.55 P. M. Six views of the seven cells at the following intervals: 

 15 min., 10 min., 10 min., 2 min., 3 min. 



5 A single migrating liver cell with its nucleus and mitochondrial granules 

 on the second day of cultivation; explant from a ten day embryo. The limits 

 of the outer edge of the cell were not visible. X 750. 



6 Two migrating liver cells, explant from an eight day embryo; 3 day cul. 

 showing nuclei each with two nucleoli and mitochondria. One cell is binucleate 

 and has many more mitochondria than the other. X 750. 



7 Two views of a liver cell, explant from a 10 day embryo, five day culture. 

 X 750. 



7o 11.26 A.M. Showing nucleus, nucleoli, mitochondria and three fat 

 globules. 



76 11.34 A.M. The same, eight minutes later. 



302 



