]Mr. H. J. Carter on two new Species o/'Gumrainege. 21 



tological element maintains its living form instead of relapsing 

 after death into a common homogeneous mass. In the true 

 sponges the softer histological elements, such as fibre-filament, 

 cells, &c., hardly do more than /oo???, as it were, in the scale 

 of development, vanishing with death into homogeneity ; while 

 in the higher developments they become permanent — e. g., the 

 histological elements in the human subject. Homogeneity of 

 appearance, as in the intercellular sarcode of sponges, is no 

 proof whatever of the absence of histological structure. There 

 is structure in glass, as I liave often said before ; but this cannot 

 be demonstrated. 



It is possible that the pores may be continuous, through 

 tubular prolongations, with the excretory canals, as in thefollow- 

 ing species ; but although invisible here (probably on account 

 of the thick surface-layer of spicules in the cortex), there can 

 be little doubt that the increasing size of the branches of the 

 latter, as they join one another to form a common trunk, indi- 

 cates, as in the true sponges, a current inwards through the 

 pores, and outward through the oscula. 



The ovoid cells (fig. 8, a), which are only half the size of 

 those in the following species, have been called ^' embryos '" 

 by Schmidt (Spong. adriat. Meeres, p. 42) ; and Kolliker has 

 used the same name after him, although evidently not satisfied 

 of their true import (Icones Histologics, " Feinere Bau der 

 Protozoen," p. 68, with excellent illustrations, Taf. viii. f. 18, 

 and Taf. ix. f. 10 & 11) ; but if they be the " embryos," where 

 are we to look for the adult forms ? — since, throughout every 

 part of Corticium ahyssi^ as well as in the folloAving species, 

 viz. Choyidrilla australiensis, respectively, they are all 

 alike. 



It is also possible that ova may be present, and that I liave 

 overlooked them, as they have been seen in Corticium candela- 

 brum by Kolliker, and figured [op. cit. Taf. viii. fig. 3) ; but no 

 one could confound the " ovoid cell " with an ovum, inasmuch 

 as the globular form of the latter, with evident nucleus and 

 nucleolus, nmst contrast strongly with the conoid form of the 

 ovoid cell filled with granules, in which a nucleus is only now 

 and then faintly visible. I must, then, for the present, look 

 upon these ovoid cells of the GummincEe as analogous to the 

 spheroidal groups of flagellated cells in the fibrous sponges, 

 reserving all further description of them in this respect until I 

 shall have observed and experimented on them in the living 

 state, as I have heretofore done on the true sponges. To show 

 that the cells which line the surface of the excretory or water- 

 canal {Wimpei'-Apparat of Lieberkiihn), or those of the am- 

 pullaceous sac {Wimperkorh oi Schmidt), are flagellated is not 



