Pore-area o/'Cliona corallinoides. 19 



and prcscntiiif)^ en vuusse siicli a white colour that it may be easily 

 mistaken f<»r a calcareous snonjjje), — that the branchial opening 

 in the gelatinous mass, it not homologous with, is certainly 

 analogous to the pore in the Spongiadie, and the common 

 cloaca! cavity and ftecal orifice are respectively analogous to 

 the excretory' canal-system and vent, also in the sponges, 

 while the olurality f>f eomnuinities or "systems" correspond to 

 the individual divisions of the sponge termed by Prof. Hiickel 



nersons. 



Then, too, there is a network of canals in the gehitinous 

 structure which may be the homologue of the gastroventricular 

 canals in Actinia and the coenosarc of the coral-polypes, espe- 

 cially for supplying nourishment and sustaining the vitality of 

 these parts. 



Prof. E. Ilackel's Views. 



It seems to me im])erative on all those who would write 

 anything on the 8pongiada>, and especially on thcCalcispongije, 

 to notice what has lately been put forth by one of the highest 

 authorities on the Protozoa of the present day. I, of course, 

 allude to the paper " On the Organization of Sponges and 

 their Relationship to the Corals," to whicli is appended a 

 " Prodromus of a System of Calcareous Sponges," by Prof. 

 E. Hiickel (Jenaische Zeitschrift, B. v. pp. 207-254; trans- 

 lated by W. S. Dallas, F.L.S., in the ' Annals,' Jan. 1870, 

 vol. V. pp. 1 et seqq.). 



In this paper, at p. 11 (translation), we find the following 

 statement : — 



" ^liklucho has already shown that in a great many sponges 

 the mouth or osculum by no means j^ermits only the outflow, 

 but also the infloAV of water. 1 have repeatedly convinced 

 myself, by my own observations, of the correctness of this 

 assertion. Consequently the mouth in many sponges, just as 

 in the corals, serv'es for both the reception and expulsion of 

 the water and the nutritive constituents contained in it." 



And at p. 6, — " I start with the following general proposi- 

 tion : — The sponges are most nearly allied to the corals of all 

 organisms." 



At p. 9 : — " I do not, like most authors, regard the charac- 

 teristic canal-system of sponges as something quite specific 

 and peculiar to this class, an arrangement sui generis^ but 

 share in the opinion of Leuckart and Miklucho, that it is 

 essentially homologous with the coelenteric vascular system or 

 gastrovascular apparatus of the Corals and Hydi-omeduste — 

 in fact, of all the Acalepha3 or nettle-animals. Indeed I am 



2* 



