No. 3.] PHOSPHORESCENT ORGANS. 679 



the latter for over two-thirds of its surface (PI. XXXVIII, Fig. 

 4, and PI. XXXIXf Fig. 5). The reflector is composed of con- 

 nective tissue, the matrix of which is modified into peculiar fine 

 strands or fibrils, called spicules. These spicules very strongly 

 reflect light. This property is very manifest even in the thin- 

 nest of sections where the reflector is dark gray or brown by 

 direct light but bright silvery by reflected light. The spicules 

 form a dense mass of fibrils somewhat regularly parallel with 

 the surface of the lens. Small oval nuclei are scattered 

 throughout the reflector, also a certain number of ordinary 

 connective-tissue fibrils are scattered among the spicules, espe- 

 cially toward the periphery of the cup. That these fibrils are 

 not " calcareous spicules," as von Lendenfeld describes for 

 phosphorescent organs of Scopelus and other deep-sea forms, 

 is evident, since they are not altered by nitric acid, nor, in fact, 

 by any of the numerous fixing reagents used in their preparation. 

 Small blood vessels are found in the reflector, but only as 

 they pierce the structure to reach the gland within. 



4. The Pigvtent. 



The pigment mass is composed of the large, many-branched 

 type of cells characteristic of the pigment cells of the skin of 

 fishes and amphibia generally. The cells are located around 

 the outer and deeper surface of the reflector and vary in number 

 in different organs. They are sometimes so numerous as to 

 form dense masses, and again, as in the ventral or anal rows, 

 there may be only three or four such cells to the organ. 



IV. Nerve Supply of the Phosphorescent Organs. 



A most diligent and persistent effort was made to demon- 

 strate the presence of a special nerve supply to the phospho- 

 rescent organs. Numerous preparations of the skin containing 

 the organs were prepared by the methods which give specific 

 nerve staining. By the iron-haematoxylin method and by the 

 gold-chloride method, no nerves could be distinguished in the 

 organs. By the Golgi method beautiful preparations were 



