CORPUSCLES OF MARINE WORMS. 143 



of these deutoplastic products in corpuscles. My friend, 

 Mr. E. S. Goodrich, has described a remarkable structure 

 in certain of the coelomic corpuscles of the oligochsete 

 worm, Enchytraeus hortejisis* It consists of a refringent, 

 thick disc, its flat surface next the nucleus of the corpuscle. 

 "When the disc comes in contact with distilled water, or 

 even salt solution, it appears that it is really formed of a 

 long thread of transparent, homogeneous substance, coiled 

 like a rope. The thread, after making its appearance 

 after coming in contact with a foreign liquid, gradually 

 unwinds, forming a tangle of loops ; but no ends have 

 ever been seen. The thread is stained yellowish brown 

 with iodine, is dissolved with difficulty on heating with 

 caustic potash, and, with acetic acid, is first turned into 

 a coagulated mass, and then for the most part dissolved. 

 Thus the chemical nature of the thread is obscure. I 

 have noticed somewhat similar threads in the coelomic 

 fluid of Chcetopterus. 



These rods and threads are instances of the occurrence 

 of deutoplastic products in corpuscles. The chief points 

 about them which demand explanation are, perhaps, the 

 curious variety of forms they assume ; their chemical 

 nature, origin, and fate ; and their purpose. 



Their forms are, perhaps, partly dependent on mechanical 

 forces acting within the cell ; but Schaeppi makes the 

 significant statement, with regard to Ophelia, that whereas 

 chlorogogen — he is speaking of chitinous chlorogogen — 

 is secreted only on one side of a nucleus, guanin is secreted 

 all round it. For this, at any rate, there is no obvious 

 mechanical reason. 



I have already dealt with the chemical nature of the 

 products. 



* Goodrich, " Quar, Jour, Micr. Sci.," vol, XXXIX., part 1, p. 57 ; 



