CHAPTER XXXVI. 517 



HAVET (La Cellule, xvii, 1900, p. 353) has also had results with 

 the Golgi method on this form, and also with thionin (after fixing 

 with sublimate), which demonstrates tigroid substance. 



Cercarice. SCHWARZE (Zeit. wiss. ZooL, xliii, 1886, p. 45) found 

 that the only fixing agent that would preserve the histological detail 

 of these forms was cold saturated sublimate solution warmed to 

 35 to 40 C. 



For an " indifferent " liquid, HOFMANN (ZooL Jahrb., xii, 1899? 

 p. 176) takes 1 part of white of egg in 9 of normal salt solution. 



969. Turbellaria. BRAUN (Zeit. wiss. Mik., iii, 1886, p. 398) gets 

 entire animals (Rhabdocoela) on to a slide, lightly flattens out with 

 a cover, and kills by running in a mixture of 3 parts of liquid of 

 Lang with 1 of 1 per cent, osmic acid solution. (Bo'HMiG [ibid.], 

 commenting on this, says that for some of the tissues, such as 

 muscle and body parenchyma, nitric acid and picro-sulphuric acid 

 are very useful.) Sections may be made by the paraffin method. 



DELAGE (Arch, de Zool. exp., iv, 2, 1886) recommends fixation (of 

 Rhabdoccela Acoela) by an osmium -carmine mixture, for which see loc. 

 cit., or by concentrated solution of sulphate of iron. Liquid of Lang was 

 not successful. 



For staining, he recommends either the osmium -carmine or impreg- 

 nation with gold (| formic acid, two minutes ; 1 per cent, gold chloride, 

 ten minutes ; 2 per cent, formic acid, two or three days in the dark). 



BOHMIG (Zeit. wiss. Mik., iii, 1886, p. 239) has obtained instructive 

 images with Plagiostomidse fixed with sublimate and stained with the 

 osmium -carmine. 



GRAFF (Turbellaria Acoela, Leipzig, 1891 ; Zeit. iviss. Mik., ix, 

 1892, p. 76) says that chromo-aceto-osmic acid, followed by heema- 

 toxylin, is good for the skin, but not for the Rhabdites, which in 

 Acoela and Alloioccela seem to be destroyed by swelling. The same 

 method is also good for the parenchyma of Amphichcerus cinereus, 

 Convoluta paradox^ and C. sordida. Sublimate is good for Convoluta 

 Roscoffensis. The nervous system may be investigated by the 

 methods of DELAGE. 



For Dendroccela sublimate solutions, sometimes hot, appear 

 indicated for fixing ; see the mixture of LANG. 64, also CHICHKOFF 

 (Arch, de Biol, xii, 1892, p. 438). 



ARNOLD (Arch. Zellforsch., iii, 1909, p. 433) kills Dendroccelum in 

 extension (?) with strong liquid of Flemming. 



OESTERGREN narcotises Dendrocoelum with his ether- water, 18. 



JAENICHEN (Zeit. wiss. Zool., Ixii, 1896, p. 256) advises for 

 Planaria, eyes especially, picro-sulphuric acid for an hour or two ; 



