METHODS FOR INVJiRTEBfiATES. 451 



on account of the carbohydrates in the cell. Sublimate is 

 best. 



857. Nervous System of Pulmonata.— B. de Nabxas [Act. Soc. 

 Liiin. Bordeaux, 1894; Rech. Hist, centres nerveux, des 

 Gasteropodes, 1894, p. 23) opens the animals and fixes the 

 ganglia for one hour in a mixture of 6 parts glacial acetic 

 acid to 100 of 90 per cent, alcohol, or for fifteen to twenty 

 minutes in 5 per cent, sublimate with 5 per cent, acetic acid. 

 He stains in bulk, with Renaut's hsematoxylic eosin, or 

 R. Heidenhain^s hsematoxylin, or a copper liEematoxylin of 

 Viallaues, § 874, and imbeds in paraffin. He also stains by 

 the rapid method of Golgi, imbedding, however, the ganglia 

 in celloidin directly after the hardening in osmic acid and 

 bichromate, and treating the sections with the silver (p. 34). 

 He stains with methylen blue by treating the ganglia in situ 

 for twelve to twenty-four hours with a 1 per cent, solution. 



Deeyer {Zeit. wiss. Zuol., xcvi, 1910, p. 380) narcotises 

 Nudibranchs with cocain, and for studying the nerves fixes 

 them with Mayek's picro-formol, puts for a week into a 

 mixture of 1 grm. of iron alum with 2 c.c. of formol and 40 

 uf water, makes sections and stains with iron hsematoxylin. 



See also, for nerve-cells, McCluke, Zool. Jahrb., 1898, 

 p. 17 (Mann's methyl blue and eosin, or Bbnda's safranin 

 and Lichtgriin), and Legbndee, Arch. mic. Anat., x, 1909, 

 p. 312. 



858. Eyes of Gastropoda (Flemming, Arch. mile. Anat., 1870, 

 p. 441). — To obtain the excision of an exserted eye, make a 

 rapid cut at the base of the peduncle, and throw the organ 

 into very dilute chromic acid, or 4 per cent, bichromate ; 

 after a short time it will evaginate, and remain as completely 

 erect as if alive. Harden in 1 per cent, osmic acid, in 

 alcohol, or in bichromate. 



Smith {Bull. Mus. Gomp. Zool. Harvard, xlviii, 1906, 

 p. 238) macerates eyes for at least two days in 9 parts of 

 water with 1 of weak mixure of Flemming, followed by 

 glycerin of 10 per cent. He bleaches them (in sections) 

 with nitric acid and chlorate of potash. 



859. Eyes of Cephalopoda and Heteropoda (Gkenachee, Ahh. 

 naturf. Ges. Halle-a.-S., Bd. xvi, 1896, p. 213). — Depigment 



