502 METHODS FOR INVERTEBRATES 



DREYER (Zeit. wiss. Zool., xcvi, 1910, p. 380) narcotises Nudi- 

 branchs with cocaine, and for studying the nerves fixes them with 

 MAYER'S picro-formol, puts for a week into a mixture of 1 grm. of 

 iron alum with 2 c.c. of formol and 40 of water, makes sections and 

 stains with iron hsematoxylin. 



See also, for nerve-cells, McCLURE, Zool. Jahrb., 1898, p. 17 

 (MANN'S methyl blue and eosin, or BENDA'S safranin and Lichtgriin), 

 and LEGENDRE, Arch. mic. Anat., x, 1909, p. 312. 



935. Eyes of Gastropoda (FLEMMING, Arch. mik. 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. Comp. Zool. Harvard, xlviii, 1906, p. 238) 

 macerates eyes for at least two days in 9 parts of water with 1 of 

 weak mixture of Flemming, followed by glycerin of 10 per cent. 

 He bleaches them (in sections) with nitric acid and chlorate of 

 potash. 



936. Eyes of Cephalopoda and Heteropoda (GRENACHER, Abh. 

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

 hydrochloric acid (in preference to nitric acid). The mixture 574 

 may also be used. If you stain with borax-carmine and wash out 

 in this mixture, the pigment will be found to be removed quicker 

 than the stain is washed out. 



LENHOSSEK (Zeit. wiss. Zool, Iviii, 1894, p. 636 ; Arch. mik. 

 Anat., xlvii, 1896, p. 45) applies the method of GOLGI to the eyes of 

 Cephalopods. 



Similarly KOPSCH (Anat. Anz., xi, 1895, p. 362), but using formol 

 instead of the osmic acid. 



HESSE (Zeit. wiss. Zool., Ixviii, 1900, p. 418) fixes eyes of Hetero- 

 poda with 1 of formol to 4 of water, and (p. 257) bleaches those of 

 Cephalopoda by the methods of GRENACHER and that of JANDER, 

 575. 



See also MERTON, ibid., Ixxix, 1905, p. 326. 



937. Eyes of Lamellibranchiata. See PATTEN, Mitth. Zool. Stat. 

 Neapel, vi, 1886, p. 733, and KAWITZ, Jena. Zeit. Naturw., xxii, 

 1888, p. 115, and xxiv, 1890, p. 579 (bleaches with caustic soda) ; 

 see 576. HESSE (op. cit., last , p. 380) employs the method of 

 JANDER for Area. He fixes the eye of Pecten in 10 per cent, formol 

 for five minutes, followed by sublimate or picro-nitric acid. 



