ox DEVELOPMEXï ETC. OF PJIOEONIS. 567 



Spheres in iresli speciiiieiis. They do not constantly iidhere to 

 the stomaeh walls as AViLSOX and some others have remarked, 

 l)ut are very trecpiently fonnd floating freely in the collar cavity, 

 showing that there exists no direct connection with the sj)lanch- 

 nic walls. This fact may he clearly ^een in iig. ~)o {corp.}, where 

 the mass is located at an appreciahle distance from the stomach 

 walls [^liji:). The same state was also ohservi-d in a Id-ai'med 

 larva of the same type. Besides, I have noticed at these stages 

 of growth two sorts of corpnscles in the masses: the one sort is 

 lariie and s(jmewhat coarsely irraiudar ; the other is nmcli smaller 

 and iinely granular. On sections it was found that the former sort 

 is ind)edde(l here and there in groups of the latter (see Iig. 'Jo, 

 Corp.). I can not exactly see the signilicance of this fact unless 

 it he that it shows the developmental process of the Ijlood corpus- 

 cles, in which the larger ones give rise to the smaller hy division 

 (the karyokinetic figures in the former can he made out with tole- 

 ralde distinctness hy staining with eosin methylhlue). The larger 

 cells are essentially identical with the corpuscles of hoth the 

 younger (12-armed) antl the (»Ider larva? (so far as advanced as to 

 he ready for metamorphosis) of the same type. Thus it seems to 

 me prohahle, though I state this with a certain degree of reserve, 

 that these smaller corpnscles develop into the normal blood cor- 

 ])uscles of the highly advanced larva, for in the latter we no longer 

 find the smaller forms in the cor2)Uscle masses. Fig. 01 a represents 

 four corpuscle cells composing a corpuscle mass of a larva of type 

 A which has already evaginated the ventral pouch. (Jf course at 

 such a stage approaching the end of larval life, the numl)er of the 

 corpuscles is actually greatly increased as compared with that iu 

 y(junger stages. 



From the above observations it mav l)e concluded that the 



