ZOOLOGY AND BOTANY, MICKOSOOPY, ETC. 139 



slowly relaxed again, and after a few minutes were so benumbed that 

 they could be placed without harm for 10 minutes in a watery solution 

 of sublimate. The author does not recommend that sublimate should be 

 replaced by alcohol or osmic acid. Borax-carmine was used for staining 

 the animals. 



Preparing Tetrastemma melanocephala.* — Mr, A. Bolles Lee used 

 Tetrastemma melanocephala for studying spermatogenesis in Nemertines. 

 The best fixative for these preparations was found to be concentrated 

 sublimate solution with the addition of 1 per cent, acetic acid. This 

 reagent showed itself to be superior to osmic acid, chromic acid, and 

 iron chloride, all which kill less quickly, and frequently excite such 

 violent muscular contraction that the contents of the seminal vesicles 

 are greatly altered. 



The best staining solution for the sections was an alcoholic hydro- 

 chloric acid carmine (100 ccm. of 80 per cent, spirit are boiled with two 

 drops of strong hydrochloric acid and excess of carmine). From this 

 fluid the preparations are transferred to pure spirit, wherein they remain 

 until no more colouring matter is extracted. A good nuclear and double 

 stain is effected by adding a little picric acid to the spirit, the picture 

 thus obtained being sharper than that produced by borax-carmine. As a 

 preliminary to deposition in paraf&n, the author recommends cedar oil 

 in place of chloroform. Preparations are best teased out in a 4 per cent, 

 chloral hydrate solution and stained afterwards with Delafield's hsemato- 

 xylin and methyl-green. 



Karyokinesis in Euglypha alveolata.f — Dr. Schewiakoff found that 

 the best fixative was Flemming's chrom-osmium-acetic acid, but it must 

 not be allowed to act long, and the animal must be thoroughly washed 

 afterwards. Grenacher's alum-carmine and picrocarmine were the best 

 stains, but picrocarmine must be used with care, as it easily overstains. 

 The animals are then thoroughly washed, and having been passed 

 through spirit of increasing strength and oil of cloves, mounted in 

 balsam or dammar. The foregoing manipulations were carried out in 

 a watch-glass, in which the selected animal was placed. The selection 

 was made by means of a lens magnifying 30 times and a capillary tube. 



The nucleus was isolated by Biitschli's method. The animal was 

 fixed to a certain spot by pressure on the cover-glass; this pressure 

 was kept up carefully until the siliceous envelope was broken. A few 

 more taps and a to-and-fro movement of the cover-glass broke up the 

 protoplasm and isolated the nucleus. This procedure was assisted by 

 means of a stream of water added at one side in such quantity that it 

 was at once absorbed by bibulous paper at the other. 



Permanent Preparations of Fresh-water Algae.J — Dr. L. Klein re- 

 commends, for marking the position of any individual example, Schieffer- 

 decker's apparatus.§ This is in appearance and size somewhat like an 

 objective, and can be screwed on to the nose-piece. At its lower end it 

 carries a diamond point, which by aid of a screw can be moved excen- 

 trically. When used, the object is first placed in the centre of the field. 

 The nose-piece is then turned round and the tube lowered until the 



* Recueil Zool. Suisse, iv. (1888) pp. 409-30 (1 pi.). 



t Morphol. Jahrb., xiii. (1887) pp. 193-258 (2 pis. and 4 figs.). Cf. this Journal, 

 1888, p. 66. X Zeitschr. f. Wiss. Mikr., v. (1888) pp. 456-64. 



§ Described in this Journal, 1887, p. 468. 



