Pore-area o/'Cliona corallinoides. \% 



and presenting en masse such a white colour that it may be easily- 

 mistaken for a calcareous sponge), — that the branchial opening 

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

 analogous to the pore in the Sj)ongiad£e, and the common 

 cloacal cavity and fascal orifice are respectively analogous to 

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

 while the plurality of communities or "systems" correspond to 

 the individual divisions of the sponge termed by Prof. Hackel 

 "persons." 



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

 structure which may be the homologue of the gastroventricular 

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

 cially for supplying nourishment and sustaining the vitality of 

 these parts. 



Prof. E. Hackel's Views. 



It seems to me imperative on all those who would write 

 anything on the Spongiadae, and especially on theCalcispongige, 

 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 Oi'ganization of Sponges and 

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

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

 E. Hackel (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 : — 



" Miklucho has already shown that in a great many sponges 

 the mouth or osculum by no means permits only the outflow, 

 but also the inflow of water. I 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, serves 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 loitJi the coelenteric vascular system or 

 gastrovascular apparatus of the Corals and Hydromedusae — 

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



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