44 Primitive Streak and Notochordal Capiat in Chelonia. 



Diagram II. represents the condition found after the separation 

 of the entoderm and the disintegration of that portion of it which 

 forms the floor of the archenteron. In this manner, according to 

 my conception, the whole streak anterior to the neurenteric canal 

 comes to be converted into the axis of the embryo, and thus the 

 length of the notochordal canal is greatly increased. 



