ZOOLOGY AND BOTANY, MICllOSCOPY, ETC. 1095 



participates in the process. When in combination with water only, 

 the action is slower, and the nucleus alone affected, 



3. A third stain was made by substituting salicylic for boric 

 acid. 100 grms. of a saturated solution of alum, 25 centigrms. 

 carmine, and 25 centigrms. salicylic acid, are boiled together for ten 

 minutes. The fluid thus obtained has a redder hue, and its stain a 

 more vivid red than that of the preceding fluid. Vegetable and animal 

 tissues stain in about twenty-four hours. 



4. Satisfactory results were obtained by boiling 25 centigrms. 

 carmine with 50 c.c. saturated solution of picric acid for ten minutes, 

 and filtering when cold. The fluid thus obtained much resembles in 

 its action and appearance picrocarmine. 



Staining Salivary Glands.*— Dr. N. Kultschizky points out that 

 the secreting cells of the serous salivary glands of the hedgehog 

 (corresponding to the parotid of other mammals) stain badly by the 

 rapid process ; slow staining for twenty-four hours or so is better. He 

 specially recommends Prof. Kutschiu's method, which consists in 

 immersing thin sections of the organs, previously hardened in chromic 

 acid salts or alcohol, in a 4 per cent, solution of chloral hydrate 

 slightly tinged with picrocarmine. The plasma is differentiated 

 into an outer granular nucleated zone deeply stained with carmine or 

 logwood, and an inner zone, finely granular and less coloured. The 

 epithelial cells lining the small duct.s show three zones after staining 

 with logwood or carmine. 



2. The mucous glands (corresponding to sublingual of most 

 mammals ; the orbital of dogs) contain, in the fresh condition, cloudy 

 cells, which clear up with alcohol or chrome salts. The nuclei and 

 plasma stain equally well with carmine and logwood ; the epithelial 

 cells of finer ducts stain well with logwood. 



3. The mixed glands (corresponding to submaxillary of man, 

 mouse, and guinea-pig) contain two kinds of cells, (a) Muconoid 

 distinguished from ordinary mucous celLs and from serous cells by the 

 fact tliat their protoplasm is ptained deeply with carmine ; logwood 

 only stains their nuclei, {h) Serous cells, which stain slightly with 

 carmine, strongly with logwood. 



Staining with Haematoxylin.t— Mr. W. A. Haswell, in an account 

 of his experience of histological methods in connection with class- 

 work, says he finds objects which have been hardened by any of the 

 usual methods, after having been at least a fortnight in alcohol, are 

 best staiued en bloc by an aqueous solution of crystallized hjcmatoxyliu, 

 followed by bichromate of potash as recommended by lleidonhain.t 

 For most organs and tissues, pieces 1/2 in. square are most success- 

 fully and uniformly stained through by means of a 1/2 per cent, 

 solution of hematoxylin, allowed to act for ten to twenty-four hours • 

 the staining agent is followed by a 1 per cent, solution of bichromate 

 of potash, which should be allowed to act for two or three hours. It 



* Zcitschr. f. Wis8. Zwl., xli. (1884) i)p. 99-100 (1 pi.). 



t Troc. Linn. Soc. N. S. WaluH, x. (18H5) pi). 'AlC-J. 



X rflugor'a Arch. GoKamint. I'hyijiol., xxiv. (1881) p. -108. 



4 B 2 



