QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 195 



partly Tnicroscopic, partly histological, describing the nerve- 

 centres with their membranes^ the structure of nerve-trunks, 

 the Pacinian corpuscles, &c. 



2. Rcge)ieratio7i of nerve. — Benecke (' Virchow's Archiv,' 

 1873, vol. Ivii, pp. 496 — 511) has studied the histological pro- 

 cess in the regeneration of nerves after section. 



3. Ganglion-cells of the sympathetic. — Arndt ('Schultze's 

 Archiv,' x, p. 208) has investigated the structure of the 

 ganglionic cells of the sympathetic in fish, birds, mammalia, 

 and in the human subject. He worked partly on prepara- 

 tions macerated in neutral chromate of ammonia and teased 

 out, partly on hardened specimens, usinof chromic acid and 

 chloride of gold. He thus summarises his results: — 1. All 

 ganglionic cells of the sympathetic, provided with several 

 processes, that is, bipolar and multipolar cells, correspond to 

 whole groups of cells, and are derivatives of such groups. 2. 

 All unipolar ganglion-cells, on the other hand, correspond 

 to and are derived from simple cells. 3. Of the so-called 

 apolar ganglion-cells, the larger represent abnormal develop- 

 mental forms of the original embryonic cells ; the smaller are, 

 in fact, themselves embryonic cells. 



4. Cortex ofthebrain. — Golgi (' Centralblatt,' No. 51, 1873, 

 p. 806) publishes a preliminary communication on the grey 

 substance of the brain, especially with reference to the large 

 pyramidal ganglion-cells of the cerebrum, the ' basal process ' 

 of which he finds to branch and finally to enter into connec- 

 tion with the connective-tissue-cells of the cerebral cortex. 

 Similar relations he finds to exist in the cerebellum. 



5. Nervous system of Nematocla. — Biitschli, " Contribu- 

 tions to the Knowledge of the Nervous System of the Nema- 

 toda " (2 plates), ' Schultze's Archiv,' x, p. 74. 



6. Electrical organs. — Boll {' Schultze's Archiv,' x, p. 101) 

 has studied the electrical plates of the Torpedo with high 

 powers, and the same organs in Malopterurus (ibid., p. 242). 



7. Aniline blue as a stainijig material for ganglion-cells. — 

 Zuppinger (' Schultze's Archiv,' x, p. 255) recommends for 

 the demonstration of the axis-cylinder process of the ganglion- 

 cells in the spinal cord the use of soluble aniline blue, ac- 

 cording to the following method : — Sections of brain or cord 

 hardened in bichromate, and washed with acidulated water, are 

 brought into a slightly acidified solution of commercial aniline 

 blue and kept in the dark till they are stained of a tolerably 

 deep colour. The sections must not overlap or cover one 

 another. They cannot be dehydrated by alcohol, since this 

 extracts the colour, but a little absolute alcohol may just be 

 poured over them to remove some of the adhering water, and 



