294 TEGUMENTARY ORGANS. 



619. Corpuscles of Pacini (MICHELSON, Arch. f. mik. Anat., 

 1869, p. 147). Michelson found maceration for several days 

 in concentrated solution of oxalic acid useful for isolating the 

 nuclei of Pacinian corpuscles. The preparation may be sub- 

 sequently stained with carmine. 



620. Tactile Corpuscles (KULTSCHIZKY, Arch. f. mik. Anat., 

 1884, p. 358). Macerate pieces of duck's tongue for eighteen 

 to twenty-four hours in 0*1 per cent, nitric acid; then treat 

 with Ol per cent osmic acid; make sections, and stain with 

 picro-carmine. 



621. The Corpuscles of Krause (Conjunctiva) (LONGWOKTH, 

 Arch.f. mik. Anat., 1875, p. 655). A fresh bulbus is care- 

 fully extracted in toto in such a way as to spare as much con- 

 junctiva as possible; the posterior half is cleaned of its fat, 

 muscle, &c., and the conjunctiva drawn back and stretched 

 over it by means of threads passed through different points of 

 its margin. The whole is then thrown into a J per cent, 

 osmic acid solution, or hung up in a cylinder and exposed to 

 the vapour of osmic acid. It is best to let it remain twelve 

 or twenty-four hours. The epithelium is then removed by 

 rubbing with a camel-hair brush or with the finger; and 

 portions of the conjunctiva as large and as thin as possible 

 are removed and examined for corpuscles of Krause either in 

 water or 1 to 2 per cent, acetic acid. They may then be 

 stained and mounted in glycerin if desired. It is advantageous 

 to make a large number of preparations, as the corpuscles are 

 not found equally distributed in all eyes nor in all parts of 

 the conjunctiva. If a conjunctiva be divided into five segments 

 two of them will generally be found quite wanting in cor- 

 puscles, whilst the other three will contain thirty to sixty 

 of them. 



(Further information concerning the corpuscles of Pacini will 

 be given, a propos of the corpuscles of Golgi, in the paragraphs 

 dealing with Nerve-ending sin Muscle and Tendon, 635 et seq.) 



622. Organs of a Sixth Sense in Amphibia (MITROPHANOW). 

 See Zeit. f. wies. Mik., v, 4, 1888, p. 513. This paper contains 

 some details as to staining with " Wasserblau," for which 

 tee also Boil. Centralb., vii, 1887, p. 175. 



