38 



COLOR CHANGES IN ANIMALS 



that of Abramowitz, as well as from the original con- 

 sideration already set forth, it seems fair to conclude 

 that the melanophores of Fundulus possess a double 

 innervation, and that the two sets of nerve-fibers, dis- 

 persing and concentrating, are real elements in the 

 neuro-melanophore organization of this fish. It is inter- 

 esting to observe that in the figures of melanophore 

 nerves in fishes published in 1893 by Ballowitz (Fig. 27), 



Fig. 27. Innervation of a chromatophore from the perch. 

 Ballowitz, Zeit. wiss. Zool., 1893, 56, pi. 38, fig. 21. 



each color-cell receives several nerve-fibers and not sim- 

 ply one, as muscle-cells ordinarily do. Of these nerve- 

 fibers, which are sometimes rather numerous, one at 

 least is presumably a concentrating fiber and another a 

 dispersing one. From this standpoint it is indeed pos- 

 sible that melanophores may differ somewhat in their 

 functional capacities depending upon a larger or a 

 smaller number of one or other kind of fiber. Thus 

 some cells may be more active in concentrating their 

 pigment than in dispersing it in consequence of a pre- 



