172 Edwin G Conklni. 



Right or Left Half Larvae Drawn from Living Specimens from 12 Hours (Figs. 41, 42) to 2c 

 Hours (Figs. 45, 46) After the Injury of One of the First Two Blastomeres. 



Fig. 41. Posterior-dorsal view. Fig. 42. Same embryo, posterior ventral view. In both these 

 figures the muscle cells are found chiefly on one side of the notochord, but they have grown over to the 

 opposite side at the end of the tail. Fig. 43. Right half larva from right side. Fig. 44. Left half 

 larva from left dorsal side. The yellow crescent on the injured blastomere apparently occupies dif- 

 ferent positions with respect to the larva in these two figures, but it is by no means certain that the 

 convex side of the larva is morphologically the same in the two figures. 



Figs. 45, 46. Two views of one and the same left half larva. Fig. 45, from the dorsal side; Fig. 

 46, from the left side, showing two sense spots on the dorsal and two on the ventral sides. The neural 

 plate is continuous between these spots on the side next to the injured blastomere. 



