292 SUMMAKY OP CURRENT RESEARCHES RELATING TO 



lating epithelial cells. Small pieces of the tissue are placed in the 

 solution for twenty-four or forty-eight hours. They may be stained 

 afterwards with picrocarmine, but before doing so it is necessary to 

 remove all traces of the sulphocyanide by steeping the tissue in water 

 for a short time. The sulphocyanide causes a precipitation of the 

 picric acid. The cells show very distinctly an intranuclear plexus of 

 fibrils. What seems to happen is that the interfibrillar ground-sub- 

 stance of the nucleus swells up slightly, and so opens out the network 

 of fibrils. In the liver of the newt and frog an intranuclear plexus 

 of fibrils is also revealed by similar treatment. 



The intranuclear plexus is also seen in non-striped and striped 

 muscle and nerve, and in the thin cartilage of the sternum of the frog 

 or newt. The fibres of the crystalline lens after twenty-foiir or forty- 

 eight hours show a beaded appearance, some of the swellings being 

 apparently due to the action of the reagent upon some chemical con- 

 stituent of the lens fibres, and some perhaps to the swelling up of the 

 cells on the fibres. 



Preserving Insects, Crustacea, Worms, and small Vertebrates.* 

 — Professor K. Mobius finds that convenient preparations of the dif- 

 ferent stages of development of insects can be made by putting eggs, 

 young and old larvsB, pupre, and imagos in a glass tube filled with 

 spirit, and having a stopper of cotton wool, then placing them, 

 according to their age, in a stoppered upright vessel filled with 

 spirit, in the middle of which is a cylindrical glass, which presses the 

 glass tube against the side of the upright vessel. 



To make tape-worms, long nemertines, long annelids, and similar 

 organisms satisfactorily visible, he rolls them spirally on a thick 

 glass tube and then places them in an upright cylindrical vessel of 

 spirit only a little wider than the tube. The worm is fastened to the 

 top and bottom of the latter by means of a fine white-silk thread, or, 

 better still, with isinglass.| 



Very instructive sections of small mammalia, birds, frogs, fishes, 

 and Crustacea, can be made by attaching them to a board, dorsally, 

 ventrally, or laterally, according to the section, and imbedding them 

 in a freezing mixture, until they are quite frozen through. Then 

 cut them with a broad-bladed knife, or saw if necessary, attach to 

 the section-plane a glass plate, and lay the preparation in strong 

 spirit until all viscera become so hardened that they retain their 

 place. Then the preparation can be cleaned and mounted. The 

 author's museum contains preparations mounted in this way of fishes 

 in which the spinal marrow, brain, olfactory nerve, swimming bla;lder, 

 &c., are very beautifully shown. In a longitudinal section of Turdus 

 merula, the form of the air-sac is distinguishable within the breast- 

 bone. 



Mounting the Proboscis of a Ply.J — Mr. T. W. Lofthouse directs 

 the fly to be killed by putting it into a bottle containing a little 

 carbolic acid that has been rendered fluid by the addition of a drop or 



* Zool. Anzrig., vi. (1883) pp. 52-3. 



t Cf. Prof. E. Selenka, ibid. v. (1882) p. 169. 



j Microscopical News, iii. (1883) pp. 21-2 (1 fig.). 



