172 I. IJIMA : HEXACTINELLIDA. I. 



(aee pp. 154, 159). I will here add, in order to further support 

 that assumption, that the oval and relatively large nuclei figured 

 by Schulze on the chamber-wall of E. aspergillum ('87, pi. iv, 

 fig. 7) are exceedingly likely to be solitarily disposed archseocytes, 

 as one may judge not only from the position and manner of 

 their occurrence but also from their close resemblance to the 

 elements of the above mentioned ' sperm-mass ' shown by Schulze 

 in another figure (fig. 6) on the same plate. As to the groups 

 of 5-20 nuclei found by the same writer ('99a, p. 209 ; 19'«, p. 99) 

 on the chamber- wall of Schaudinnia arctica, I have already ex- 

 pressed my opinion (p. 159), which therefore need not be repeated. 



The relatively massive development attained by the arcliœo- 

 cyte congeries and the constancy and frequency of their occur- 

 rence plainly point to their high physiological significance. The 

 idea that first suggests itself is that they must be connected with 

 reproduction. And I believe that this in a great measure is the 

 fact ; but let me consider this point in my treatment of the 

 Keproductive Elements. Here I should emphasize the fact that 

 the single cells composing the congeries as described above are 

 apparently as yet in no way differentiated from the solitary 

 archseocytes Avhich have given rise to the latter by repeated 

 division and probably also by simple union. The congeries are 

 to be considered as homogeneous accumulations of simple archieo- 

 cytes, still unsettled, as it were, as to the office they should 

 assume. Considered in this light it is possible to conceive, that 

 they, though representing par excellence the A.nlage of certain 

 reproductive bodies, are under some circumstances capable, as I 

 think they are, of giving rise to certain other bodies which are 

 of service in the preservation of individuals, viz., the thesocytes. 



