554 



E. I. WERBER 



tine. No spinal cord, however, is yet seen in these sections of 

 the tail, while in more posterior sections the notochord of the tail- 

 part appears to be practically surrounded by the spinal cofd 

 (fig. 61). At the same level parts of the semi-circular canals 



Figs. 61 and 02 Camera lucida drawings of embryo in figure 44. e.v., ear 

 vesicles; hr., brain; sp.c, spinal cord; c.d., notochord; o.c, optic cup; {., intestine; 

 pi., plasma;/., fibrin. X 100. 



come into view and also a part of an obliquely cut gut-coil. A 

 few sections more posteriorly the plasma-filled space between 

 the two parts of the embryo has disappeared from view and its 

 place is now taken up largely by the obliquely sectioned intes- 

 tine which stretches across between the two parts. The latter 

 are now continuous. The spinal cord of the tail-part is now 

 restricted to the region dorsal to the notochord and can be 



