694 GREENE. 



EXPLANATION OF PLATE XXXIXf 



Fig. 5. Cross-section of a ventral organ in Porichthys notatus Girard. /, lens; 

 gh gland ; r, reflector ; W, blood vessels. In this section only a small amount of 

 pigment shows to the left. 



Fig. 6. Section of the deeper portion of a phosphorescent gland highly mag- 

 nified to show the character of the cells. Flemming preparation. 



Fig. 7. A somewhat oblique section of the deeper portion of a gland a little 

 to one side of the center of an organ. Flemming preparation. 



Fig. 8. The nerves distributed around the lens. Lens in outline. Golgi 

 preparation. 



Figs. 9-11. Sections through a ventral, a pleural, and a lateral organ, respec- 

 tively, of an embryo just before becoming free-swimming. The orientation of 

 the organ with reference to the epidermis varies according to the position on the 

 body. These three figures should follow in stage of development that shown 

 in Fig. 24. 



Fig. 12. Section of an embryonic organ just separating from the epidermis. 

 This organ shows a differentiation even before it is cut off from the epidermis. 

 Compare with Figs. 21 to 23. 



