842 SUMMARY OF CURRENT RESEARCHES RELATING TO 



30 per cent, spirit. The latter makes the tissue somewhat too brittle. The 

 best staining results were obtained from Eanvier's picrocarmine, but borax- 

 carmine, lithium-carmine, heematoxylin, and eosin were also used. The 

 lime in the shell is extracted by acting on it for twenty-foiir to forty-eight 

 hours with a concentrated solution of picric acid in an incubator, and the 

 acid removed by immersion for a similar period in water heated as before. 

 Perforation or slight fracture of the shell hastens the staining, &c. 

 Flemming's solution is not very advantageous, because it penetrates too 

 slowly. Lively movements of the spermatozoa of Cypris punctata Jur. 

 and Cyprois monacha Miill. may often be perceived after teasing open a 

 receptaculum seminis in three-fourths salt solution. The spermatic fila- 

 ment of an undetermined Cyprid was uniformly stained with methyl-green, 

 and scarcely altered at all by long immersion in concentrated hydrochloric 

 acid or caustic potash. 



Preparation of endothelium of the general cavity of Arenicola and 

 Lumbrica.* — M. H. Viallanes angesthetizes the animal by immersing it for 

 an hour in sea water to which chloroform is added. It is then spread out 

 on a wooden plate and fixed with two pins. The middle zone is opened by 

 a longitudinal incision and the integument reflected and fixed down with 

 pins. A piece of the alimentary canal and of the muscular sheath from the 

 anterior and posterior ends of the body are removed and then washed with 

 water and with an acid 0-01 per cent, solution of silver oxide. It is again 

 washed, and then placed in 36 per cent, spirit until the silver is reduced. 

 Immersion in spirit is necessary, because if reduction take place in water 

 the muscles contract and further observation is rendered difficult. When 

 the silver oxide is sufficiently reduced the piece is removed, cleared up in 

 clove oil, and mounted in balsam. This procedure brings out the endo- 

 thelial cells covering the muscles with perfect clearness. 



In order to show the endothelium covering the interannular septa the 

 following method is useful. The annelid is first syringed with one-third 

 spirit and then immersed for twenty-four hours in 80 per cent, spirit. The 

 animal is then opened, one of the septa (the third is the most perfect and 

 best for observation) isolated, carefully spread on a slide, and examined 

 after being stained with picrocarmine or eosin and logwood. By the action 

 of 30 per cent, spirit the endothelial cells are set free, and only the tissue 

 forming the framework of the septum remains. 



Preparing Eggs of Rotatoria-t — Dr. G. Tessin states that it is very 

 difficult to obtain good preparations from the small eggs of Eotatoria. With 

 those of Brachionus he usually proceeds by rapidly killing the egg in 

 chrom-acetic acid ; no distortion results. From weak they are transferred 

 to strong spirit. Picrosulphuric acid produces great distortion, and sub- 

 limate does not penetrate. Staining is only possible with hjematoxylin, as 

 carmine is useless. Creosote is the best clarifler. Paraffin only penetrates 

 with difficulty. 



Examination of Nectarial Tissue.^ — Dr. S, Stadler finds that osmic 

 acid is a test for tannin, which it stains brown to a black or blue violet. 

 If any fatty oils are present the test cannot be employed. The author, 

 who had previously used three kinds of zinc chlor-iodide solution for the 

 examination of the cell-wall and of the cuticle in nectaries, has, on account 



* Ann. Sci. Nat.— Zool., xx. (1886) 10 pp., 1 pi. 



t Zeitsclir. f. Wiss. Zool., xliv. (1886) pp. 273-302 (2 pis.). See this Journal, ante, 

 p. 94. 



t Stadler, S., ' Beitr. z. Kenntniss der Nectarien ii. Biologie der Bliiten,' 88 pp., 8 pis., 

 8vo, Berlin, 1886. 



