560 Chas. W. Hargitt 



cells of the manubriiim , particularly in the median aud terminal 

 portious, giving- to the loose tissue a distiuctly brownish color. A 

 eareful study of the orig-in and development of these granules com- 

 l)els the eonclusion that they are resulta of waste metaholism, or in 

 other words, excretory products. Wheu attention is directed to the 

 fact that the entodermal epithelium of this region has been the 

 center of active metabolism incident to the growth of the eggs from 

 the timo the gonophore bud became functionally disconnected from 

 the body of the polyp, and that in their stages of growth these 

 entoderm cells through cytomorphosis became essentially nutritive 

 cells, the foregoing eonclusion is only what might be naturally ex- 

 pected. 



In connection with these observatious it had occurred to me 

 that possibly certain of these pigment granules raight find their way 

 into the growing eggs along with nutritive matter absorbed from 

 the entoderm cells, but a eareful examination failed to show that 

 this was the case. Furthermore, since the pigmentation of the eggs 

 occurs chiefiy as they attain full growth, and coincident with the 

 metabolism involved in the phases of maturation, I incline to believe 

 that it is due in this case, as in the former, to pigment granules 

 evolved through similar cytoplasmic metabolism. This view is 

 strengthened by the fact that in the present case, as well as in 

 others well kuown, the color of the eggs diflfers from that of the 

 manubrium, to a greater or less extent. 



In a recent contribution ^ I have directed attention to the re- 

 lation of excretory processes to coloration among certain of the lower 

 invertebrates, and the facts here eited afford additioual evidence in 

 Support of the general proposition. 



Lendenfeld 2, in a criticai paper on Eucopella has briefly re- 

 ferred to the probable relation of the brownish pigment present in 

 the radial canals of the medusa to excretory processes. He ex- 

 pressly says, "Diese Pigmentmassen gleichen denen, die in dem Ento- 

 derm der Nährthiere vorkommen, durchaus und glaube ich dieselben 

 ebenfalls als ExcretionsstoÖe deuten zu sollen. Die Masse der Ex- 

 kretionsstoffe richtet sich natürlich nach der Lebhaftigkeit des Stoff- 

 wechsels und es wird deshalb nicht Wunder nehmen, wenn gerade 

 in den Radialkanälen der lebhaft wachsenden Medusenkuospen sich 

 solche Stoffe anhäufen."" 



1 Science Vol. 19 1904 pag. 132. 



2 Zeit. Wiss. Z. 38. Bd. 1883 pag. 545. 



