METHODS FOB INVEBTEDRATES. 461 



solution of Methyl blue^ which allows the course of the 

 iiephridia to be made out. 



885. Gephyrea. — Vogt and Yukg {Aiiat. Comp. Prat., p. 

 373) direct that Siphunculus nudushe kept for some days in 

 perfectly clean basins of sea waterj changed every day, in 

 order that the intestine of the animals may be got free from 

 sand, and then aneesthetised with chloroform. 



Ward [Bull. Mus. Comp. Zool., Cambridge, Harvard Coll., 

 xxi, 8, p. 144) puts them into a shallow dish with sea water 

 and pours 5 per cent, alcohol in a thin film on to the surface 

 of the water, and as soon as they make no contractions on 

 being stimulated removes to 50 per cent, alcohol. 



Lo Bianco says killing with 0'5 per cent, chromic acid or 

 with O'l per cent, chloral hydrate in sea water may be tried. 

 Phascolosoma and Phoronis should be treated by the alcohol 

 method, larvee of Sipunculus with cocaine, § 21. 



Apel {Zeit. wiss. Zool., xlii, 1885, p. 461) puts Priapulus 

 and Hal'icrrjpius into a vessel with sea water and heats on a 

 water-bath to 40° 0. ; or they may be thrown into boiling 

 water, which paralyses them so that they can be quickly cut 

 open and thrown into J per cent, chromic acid or picro- 

 sulphuric acid. 



886. Rotatoria. — For quieting them for study in the living 

 state, Webek {Arch, de Biol., viii, 4, 1888, p. 713) finds that 

 2 per cent, solution of hydrochlorate of cocaine gives the 

 best results. Warm water gave him good results for large 

 species, such as those of Hydatina and Brachionus. 



Haudy [Journ. Roy. Mic. 8oc., 1889, p. 475) recommends 

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

 p. 476) mentions weak solution of salicylic acid. 



VoLK {Jahrh. Hamburg, uiss. Anst., xviii, 1901, p. 164) 

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

 litre of water. Gf. § 917. 



HiKSCHFELDEK {Zcit. wiss. Zool., xcvi, 1910, p. 211) studies 

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



See also §§ 23, 24 and 27. Methylene blue, § 339, may 

 be found useful. 



Permanent preparations may be made by the method of 

 RoussKLET {Journ. Qiiekett Mic. Club, v, March, 1895, p. 1) : 

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



