THE FRAGRANCE OF CALCINEAN SPONGES. 299 



The Fnigrance of Oalcinean Sponges and the Spermatozoa of Guancha 

 and Sycon. By G. P. Bidder, Sc.D., F.L.S. 



(Plate 24.) 



[Read 6th May, 1020.] 



In collecting the characters which indicate that two completely separate 

 groups of sponges have spicules of calcite, I stated that in Calcinea " most 

 species show varieties which are coral-red and sulphur-yellow/' while in 

 Calcaronea "the sponges never show a coral-red or sulphur-yellow colour" 

 (1898c, p. 73)*. I would now suggest the possible additional group- 

 characteristic of odour. 



The scent from freshly-gathered Clathrinidpe is very noticeable. To me it 

 is stimulating and pleasurable, it has always recalled the ozone from an 

 electric discharge ; the suggestion is aromatic, it is perhaps possible to find 

 a faint association with garlic. (The efflorescence of dry-rot — curiously like 

 Guancha coriacea or Ascaltis reticulum in appearance — has a similar smell.) 



The odour of Leucandra aspera, Sycoii raphanus, and Grantia compressa, like 

 their colour, is much less noticeable than that of the Clathrinidae. Probably 

 the cause of the difference in odour is to be sought in the cause of the 

 difference in colour, that is, in the excretory granules of the cells of the skin, 

 a great part of which is soluble in distilled water, alcohol, etc. (1892 b, 

 p. 482). (See Note C, infra, p. 317.) 



I suggest that the advantage of the scenting of the water near the sponges 

 is the production of chemiotasis in spermatozoa from sponges of the same 

 species. The water of the sea must contain the spermatozoa of all the phyla 

 which inhabit it, and these will be borne in with other suspended nutritious 

 particles by the afferent currents of the sponge. But these currents are very 

 slow — in Leucandra aspera, from my measurements, about 30 /j, a second at 

 a distance of 2 - 5 cm. from the sponge, surface, — and directed progression 

 by spermatozoa of the species would therefore in still water importantly 

 increase the proportion of them which enter the sponge. Church gives 

 data for velocities of antherozoids ranging from 100 p, to 300 p. a second 

 (1919, p. 5). 



Are there flagellate spermatozoa in Calcinea? Polejaeff (1882) described 

 them in Calcaronea, but I have not seen the pulsellum-tailed spermatozoa 

 which he observed. Figs. 1 and 2, PL 24, show a free organism in a live 

 section of S. raphanus tropus aquariensis, which may or may not have 



* For references to works quoted in this paper see p. 325. 



