460 CHAPTER XXXI V. 



BENEDEN, kindly communicated to me by Dr. C. Maurice). 

 Place the corms in clean sea water, and leave them alone for 

 a few hours, in order that the zooids may become fully 

 extended, then plunge them suddenly into glacial acetic acid. 

 Leave them there for two, four, or six minutes, according to 

 the size of the corms (which are best taken of as small a size 

 as possible). Take them out of the acid with your fingers 

 (or at all events not with steel instruments, which would 

 blacken the tissues) and bring them into 50 per cent, alcohol. 

 Wash them thoroughly in that, and then bring them in the 

 usual way through successively stronger alcohols. 



I strongly recommend this process, which gives admirably 

 preserved preparations quite free from any opacity either in 

 the tissues or the tunic. The acid will not hurt the fingers 

 if they be washed immediately. 



S. Lo BIANCO recommends for this group the chloral 

 hydrate process, followed by fixation with sublimate or 

 chromo-acetic acid. 



CATJLLERY (Bull. Sc. France Belg., xxvii, 1895, p. 5) first stupefies the 

 animals with cocaine (LAHILLE, a few drops of 5 per cent, solution to 30 c.c. 

 of sea water), then fixes in liquid of Flemming or acetic acid. 



Most small pelagic Tunicates are very easily fixed with 

 osmic acid or acid sublimate solution. 



I have found the acetic acid process very good for Pyro- 

 soma. Lo BIANCO puts them for a quarter of an hour into 

 50 per cent, alcohol containing 5 per cent, of hydrochloric 

 acid, then into successive alcohols, beginning with 60 per 

 cent. He kills the hard forms of Salpa with acetic acid of 

 10 per cent., the semi- hard ones with 1 per cent, chromic 

 acid containing 5 per cent, acetic acid, the soft ones with 1 

 per cent, chromic acid containing ^ per cent, osmic acid, 

 Doliolidae with sublimate, or the above osmic mixture, or 

 a mixture of 10 parts 10 per cent, solution of sulphate 

 of copper with one part concentrated sublimate solution. 



Molluscoida. 



825. Bryozoa. For some methods of killing and fixing see 

 Hj 18, and 19. S. Lo BIANCO employs for Pedicellina 



