INVERTEBRATES 593 



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 haMuatoxyUn. 



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

 (Mann's methyl blue and eosin, or Benda's safranin and Licht- 

 griin). and Legexdre, Arch. mic. Anat., x, 1909, p. 312. 



1173. Eyes of Gastropoda (Flemming, Arch. mik. Anat., 1870, 

 p. 44-1). 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. 



1174. Eyes of Cephalopoda and Heteropoda (Grenacher, 

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

 with hydrochloric acid (in preference to nitric acid). The mix- 

 ture § 611 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. rciss. Zool., Ixviii, 1900, p. 418) fixes eyes of 

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

 those of Cephalopoda by the methods of Grenacher and that 

 of Jander, § 617. 



See also Merton, ihid.. Ixxix, 1905, p. 326. 



1175. Eyes of Lamellibranchiata. See Patten, Mitth. Zool. 

 Stat. Neapel, vi, 1886, p. 733, and Rawitz, Jena. Zeit. Natiirw., 

 xxii, 1888, p. 115, and xxiv, 1890, p. 579 (bleaches with caustic 

 soda) ; see § 619. Hesse {op. cit., last §) 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. 



1176. Shell. Sections of non-decalcified shell are easily obtained 

 by the usual methods of grinding, or, which is often a better 

 plan, by the methods of v. KocK or Ehrenbaum. Moseley 

 {Quart. Journ. Mic. Sci. (2), xxv, 1885, p. 40) decalcifies with 

 nitric acid of 3 to 4 per cent, and then makes sections. This 

 method serves for the study of the eyes of CniTOXiDiE. 



