438 TJie Structure and Life- History of a Sponge. [Sess. 



of a honeycombed structure, and consists, in fact, of the egg-capsules of the 

 common whelk (Bucciimm undatum). When dried and pulverised, it has 

 an irritating effect upon the skin. Hence the local name — ' fyke ' = fidget." 

 We have here a curious mixture of truth and error, for sea-fyke, while it 

 iindoubtedly has the effect here attributed to it, does not consist of the 

 egg-capsules of the whelk, but is a sponge of the genus Halichondria ! 

 A racy book entitled ' Chronicles of the Gumming Club, and Memories of 

 Old Academy Days,' by Lieut.-Col. Fergusson, was privately printed a short 

 time ago, in which the dire effects of sea -fyke among the Edinburgh 

 Academy boj^s are duly chronicled ; and it is stated that Professor P. G. Tait, 

 himself an old Academy boy, had sent a specimen, procured from a New- 

 haven fisherman, to the Edinburgh University experts, who jjronounced it 

 to be Halichondria coralloides. A portion of this specimen, duly labelled, 

 was afterwards " deposited in the chest containing the archives of the Cum- 

 ming Club, and is at the disposal of whatever competent scholar may show 

 evidence of a desire to approach the subject in a proper spirit." H. coral- 

 loides, however, though found in the Firth of Forth, is a deep-sea sponge, 

 not " found on the sea-shore," as the biographers of Professor Clerk Maxwell 

 assert sea-fyke to be, and not at all common as a British species ; whereas 

 the ubiquitous H. panicea is equally valuable for the purpose specified, and 

 is more easily got, being a rock-pool dweller. Dr Johnston, in his ' History 

 of British Sponges and Lithophytes,' gives for this latter species the syn- 

 onyms of " Spongia urens, Ellis, vel urtica, Risso," and adds : "When dry, 

 the sponge is friable, and the powder has the property of producing an in- 

 tolerable itching when rubbed on the skin, as is well known to mischiev- 

 ous boys." The youth of Newhaven, however, do not seem to be aware of 

 the fact that the easily procurable " crumb-of-bread sponge " possesses this 

 valuable property, as I find that those of them who know anything of 

 " sea-fyke " are of the opinion that, according to the traditions of the village, 

 the only genuine article " comes out of the deep sea," and is got from the 

 fishermen's lines. Perhaps it might be a humane act not to disturb this 

 ancient belief ! 



In illustration of the above paper, a large number of sponge spicules 

 were shown under the microscope, as well as spicules from Gorgonia, 

 Alcyonaria, Plexaura, &c. The following preparations of British sponges 

 were also exhibited : — 



1. Section of Pachymatisma Johnstonia, named in honour of Dr George 



Johnston, showing needle-shaped and radiate silicious sjiicules, with 

 gemmules scattered through the tissue. 



2. Section of Grantia compressa, showing clavate and tri-radiate calcar- 



eous spicules. 



3. Section of Tethj^a Lj'ncurium, Lamarck, showing needle-shaped 



silicious spicules in bundles, and also the beautiful stellate spicules 

 of the ectoderm. 



4. Section of Sycon ciliatura, showing the flagellated cells lining the ex- 



halant canals. 



5. Gemmules or winter-eggs, from Geodia sp. 



