INVERTEBRATES 605 



thick syrup added drop by drop to the water. Hudson {ihid., 

 p. 476) mentions weak solution of salicylic acid. 



VoLK (Jahrb. Hamburg, idss. Anst., xviii, 1901, p. 164) quiets 

 them in quince mucilage, 40 grm. of the seeds to 1 litre of 

 water. 



HiRSCHFELDER (Zcit. wiss. ZooL, xcvi, 1910, p. 211) studies 

 them living in neutral red of 1 : 50,000. 



See also §§ 13 and 26. Methylen blue, § 376, may be 

 found useful. 



Permanent preparations may be made by the method of 

 RoussELET {Journ. Quekett Mic. Club, v, March, 1895, p. 1) : 

 The animals are got together in a watch-glass and are narcotised 

 by adding to the water at intervals a few drops of the mixture 

 given in § 13. 



As" soon as the cilia have ceased to beat, or are seen to be on 

 the point of ceasing to beat, they are fixed by adding a drop of 

 liquid of Flemming or of J per cent, osmic acid. After half a 

 minute or less the animals are taken out with a pipette, and 

 thoroughly washed by passing them through two or three watch- 

 glasses of distilled water. They are then definitely mounted in a 

 mixture of formol 2| parts, distilled water 37| parts. 



ZoGRAF {Comptes Rend., cxxiv, 1897, p. 245) narcotises as 

 RoussELET, but without the spirit, fixes with osmic acid for 

 two to four minutes, then replaces this by raw pyroligneous 

 acid diluted with 8 to 10 volumes of water, and after five to ten 

 minutes washes in several changes of water, and passes through 

 successive alcohols into glycerin or balsam. 



Lexssen {La Cellule, xiv, 1898, p. 428) for the embryology 

 of Hydatina, kills with hot saturated sublimate, dehydrates, 

 stains lightly, imbeds in paraffin and stains with h?emalum. 



HiRSCHFELDER {op. cit., supra) narcotises with cocaine, and 

 fixes with Fol's picro-chromic acid. 



Beauchamp {Arch. Zool. Exper., iv, 1906, p. 29) finds 1 per 

 cent.'stovaine better than cocaine for some forms. He {ibid., 

 X, 1909, p. 77) fixes for five to ten minutes in 4 parts of 1 per 

 cent, osmic acid, with 1 of 6 per cent, sublimate, and 5 of 5 per 

 cent, bichromate of potash, and 1 drop of acetic acid for each 

 2 c.c, and imbeds in celloidin, and then through chloroform in 

 paraffin (three to ten minutes). 



See also Tozer {Journ. Roy. Micr. Soc., 1909, p. 24). 



1205. Acanthocephali. Saefftigen {Morph. Jahrb., x, 1884, 

 p. 120) obtained the best results by killing gradually with 0-1 

 per cent, osmic acid ; the animals placed in this contract during 

 the first hours, but stretch out again and die fully extended. 

 Similarly with 0-1 per cent, chromic acid ; Echinorhynci live 

 for days in it, but eventually die fully extended. 



Hamann {Jen. Zeit., xxv, 1890, p. 113) has succeeded with 



