THE DEVELOPMENT OF AMPHIOXUS 



57 



pg 



vg 



FIG. 21. Diagrams of sections through the gonads of Amphioxus in three 

 stages of development. After Cerfontaine. Atrial surface toward the right. 

 A. Early stage. B. Intermediate stage. C, Late stage showing definitive 

 arrangement. 6, Peribranchial (atrial) epithelium; c, cicatrix; /, true follicular 

 epithelium; fe, external layer of follicular epithelium; g, gonocoel; ge, germinal 

 epithelium; 01, primary ovarian cavity; 02, secondary ovarian cavity; pg, parietal 

 layer of gonocoel; v, cardinal vein; vg, visceral layer of gonocoel. 



