( 228 ) 

 PEOGKESS OF MICKOSCOPICAL SCIENCE. 



A New Mode of Colouring Sections of the Nervous System. — 

 M. Mathias Duval describes the following method recently pursued 

 by himself, detailed in M. Robin's 'Journal de I'Anatomie ' (Feb- 

 ruary 1876). He states that whilst it is generally applicable, it is 

 especially so with sections of the cerebro-spinal axis. The process 

 consists of two methods, one of which is very old. It is, in fact, the 

 addition of the blue coloration of aniline to the red colour of 

 carmine, from which there results a violet tint more or less intense, 

 and according to the nature of the parts of very varying degrees of 

 tinting. Sections thus prepared should be mounted in Canada balsam 

 or dammar resin. This is how the author proceeds : The section is at 

 first coloured with carmine, according to the ordinary process ; it 

 should then, to be dehydrated, be submitted to the successive action 

 of alcohol of thirty-six degrees, and of absolute alcohol. After the 

 action of the latter it is plunged for a few minutes (from five to 

 twenty minutes) into an alcoholic solution of aniline blue (aniline 

 blue soluble in alcohol). In taking it from this bath it is placed 

 in turpentine to be mounted in the ordinary way. Thus obtained, 

 the pieces present a fine violet colour, which one would think 

 too deep, but which present an extreme transparency beneath the 

 microscope. The nerve-cells and axis-cylinders are indicated with 

 the most marvellous distinctness. In fact, the author characterizes 

 this method as compared with the simple preparation with car- 

 mine, by stating that the new preparation is compared with the old 

 as a neat water-colour painting is as contrasted with a badly worked 

 lithograph. The principal advantages of this method may be judged 

 by what the author says may be seen in the sections : (1) The nerve- 

 cells and axis-cylinders are of a violet, bordering on red. (2) The 

 vessels are of a violet, bordering on blue, and are very distinct. 

 (3) The envelopes (pia mater) which proceed from the pia mater and 

 penetrate into the nervous centres, are all coloured a pure blue, so 

 that they are readily distinguished from the rest. The author 

 promises, in a future number, to express more at length the great 

 advantages of this method. 



Belations of Nerves to Ganglia. — A note on this subject has been 

 recently presented to the French Academy by M. Ranvier, who states 

 that minute experiments made by the writer have demonstrated to him 

 that almost all the nerve-tubes which set out from the ganglion-cells, 

 instead of preserving their individuality in directing themselves 

 towards the centre or towards the periphery, presented T-shaped 

 anastomoses with the tubes coming from the posterior roots. 



Structure of the Pancreatic Cells, observed during Digestion. — It is said 

 in a paper by Herr A. Heidenhain, which appears in Pfliiger's ' Archiv ' 

 (vol. X.), that the following appearances were successively presented by 

 the cells of the pancreas at the different stages of digestion : — 1. During 

 hunger the granular inner zone occupies the larger, the homogeneous 



