E. MAESHALLI. — DEVELOPMENT OF HEXASTERS. 197 



two of extreme fiueness are occassioually fouud to extend from 

 the wall to the scleroblast-mass. Otherwise the space between 

 the two seems to be quite empty. 



So far in common as to both the Horicome and the graphio- 

 come. Let me now supplement this account by dealing separately 

 with each, referring to the figures I have given in PI. V. 



As to the floricome, the earliest stage I have as yet dis- 

 covered (fig. 29) shows the ends of the principals only slightly 

 swollen in a knob-like manner. In the total absence of termi- 

 nals, I have relied on the following peculiarities in identifying it 

 as an incipient floricome, and not as a future graphiocome : viz., 

 the relatively shorter and thinner principals, the somewhat 

 smaller size of the scleroblast-mass, and the number of nuclei in 

 that mass which is smaller than in the case of graphiocomes. 



Fig. 30 shows a decidedly more advanced stage in the flori- 

 come development. The first rudiments of the terminals are 

 present in a whorl around the outer, convex, terminal surface of 

 each principal. — As to the change in form of the terminals and 

 their perianths during the later stages of development, I have 

 nothing to add to the accounts I have given on pp. 52 & 76. 



Fig. 31 illustrates a nearly or quite mature floricome in its 

 relation to the immediately surrounding soft parts. The sclero- 

 blast nuclei form a berry-like group at the center. The capsular 

 wall, still plainly recognizable, stretches between the basal parts 

 of the terminal perianths. A number of fine trabeculse join the 

 terminals, some running between these or across the internal 

 hollow of the perianth. As often as not 1-3 nuclei occupy a 

 position at the fundus of the hollow just referred to, while a few 

 more may be found at indefinite positions in the proximity of 



