118 Mr. H. J. Carter on the 



from thence into the parenchyma or semiopaque structure of 

 the body, where they finally come into contact with the spon- 

 gozoa (" Geisselzellen ") of the ampullaceous sacs (" Geissel- 

 kammern "), and there rest for about fifteen minutes, when 

 there is a cessation of the circulation, during which the vent 

 is closed and the tubular process on which it was projected is 

 retracted. After the expiration of the time mentioned the 

 11 tubular process " is again put forth, and the vent at the 

 end of it opened, when the red particles, now probably sepa- 

 rated from their gummy constituents, may be seen to pass 

 from the ampullaceous sacs into the large branches of the 

 excretory canal-system, and so finally out at the vent. 



All this is plain ; but as stated (I. c.) I could not follow 

 the particles from the cavity of the investing membrane 

 through the parenchyma, although I could see when they 

 arrived at the ampullaceous sac, and by tearing the latter to 

 pieces, that the spongozoa had finally taken them into their 

 bodies. 



This view continued in much the same state until 1877, 

 when Dr. F. E. Schulze, of Gratz University, began to publish 

 those illustrated descriptions in the Zeitschr. f. wiss. Zool. 

 which have made a notable epoch in the advancement of 

 spongology (Bd. xxviii -xxxv.), wherein he shows that, in 

 Halisarca hoularis (Bd. xxviii. Taf. ii. fig. 13), there is a 

 plurality of small holes in the ampullaceous sac, and especially 

 in Spongelia avara (Bd. xxxii. S. 134, Taf. viii. fig. 5), where 

 " 20-30 " might be numbered in addition to the large aperture 

 which communicates directly with the branch of the excretory 

 canal-system ; while in the Chondrosida3, the Aplysinidas, and 

 Corticium candelabrum only two apertures are represented, 

 viz. an afferent and an efferent aperture. Schulze also pointed 

 out in 1875 that similar small apertures existed in the 

 chamber-walls of Sycandra raphanus (Bd. xxv. Suppl. Taf. 

 xviii. fig. 1). 



Thus it might be inferred that there is a distinct pore- 

 system which carries the particles of nutriment direct from 

 the dermis to the spongozoa, as direct as that which takes 

 them away ; but this we shall see is not so, for the particles 

 that are taken in with the water through the pores of the 

 dermis fall directly into the subdermal cavities, and pass 

 thence into the large excretory canals, from which they are 

 afterwards deflected to their destination through smaller 

 branches, whose apertures may be seen in the walls of the 

 former (PI. IV. fig. 5, e) . 



This I pointed out in 1869 ( l Annals,' vol. iv. p. 192, 

 pi. vii. fig. 5) in Grayella cyathophora, where the pore-area, 



