INVERTEBRATES 615 



1223. Zoantharia with Calcareous Skeletons are difficult to deal 

 with on account of the great contractility of the polyps. Sub- 

 limate solution, which ought very often to be taken boiling, 

 sometimes gives good results. 



See also Lo Biaxco, loc. cit., p. 446. 



Sections. See §§ 910 and 202, for undecalcified specimens. 



1224. The Alcyonaria have also extremely contractile polyps. 

 In a former edition Lee suggested for their fixation either hot 

 sublimate solution or glacial acetic acid (§ 12). S. Lo Bianco 

 has since recommended essentially similar processes. Garbini 

 [Manuale, p. 151) drenches them with ether, and brings into 

 strong alcohol. 



Wilson (Mitth. Zool. Stat. Neapel, 1884, p. 3) kills Alcyonaria 

 with a mixture of 1 part of strong acetic acid and 2 parts of 

 concentrated solution of corrosive sublimate, the animals being 

 removed as soon as dead and hardened for two or three hours 

 in concentrated sublimate solution. 



1225. Zoantharia and Alcyonaria. Braun {Zool. Anz., 1886, 

 p. 458) inundates Alcyonium palmatum, Syynpodium coralloides, 

 Gorgonia verrucosa, Caryophyllia cyathus, and Palythoa axinellce 

 with a mixture of 20 to 25 c.c. of concentrated solution of sub- 

 limate in sea-water with 4 to 5 drops of 1 per cent, osmic acid, 

 and after five minutes passes into successive alcohols. 



(This method also gives good results with Hydra and some 

 Bryozoa and Rotifers.) 



See also §§ 14 et seq. 



BujOR {Arch. Zool. Expe'r., ix, 1901, p. 50) kills Veretillum in 

 sea-water containing 10 per cent, each of formol and ether, and 

 after a minute passes into 2 per cent, solution of formol in sea- 

 w^ater. 



1226. Hydroidea in General. Directly the tow-net comes on 

 board, the Plankton must be poured into a glass jar and jelly 

 fishes at once picked out by means of a lifter or pipette, and 

 placed in another very clean jar of sea-water. Leave in this 

 jar for half an hour to allow organisms to recover from shock. 

 Note that the slightest trace of chemicals in the jar will prevent 

 their expanding. The secret of successful preservation depends 

 on keeping the animals in motion while you pour in the fixer. 

 First stir the organisms very slowly and gently, and when all 

 are in motion begin to pour the formalin slowly down the side of 

 the vessel. About 10 c.c. of 10 per cent, formalin should go to 

 100 c.c. of sea-water, but better more than this quantity. Keep 

 stirring for at least two minutes after addition of fixer. Leave 

 for a few hours and then transfer to 5 per cent, formalin ; finally 

 store in 10 per cent. To obtain medusae in a nice state of expan- 

 sion it is necessary to use an anaesthetic (see especially §§ 16 et seq.). 

 Hydrochloride of cocaine is possibly the best ; use a 1 or 2 per 



