xxiv Journal of Comparative Neurology. 



were placed in pyroligneus acid 6-10 hours and dehydrated in alco- 

 hols, infused with xylol and imbedded in paraffin. The nerves after 

 this treatment are colored greyish blue, the muscles are brownish and 

 the connective tissue remains pale. 



By this means the author demonstrated the existence of trans- 

 verse connections between the longitudinal nerve trunks in the pro- 

 glottides. A ganglionic enlargement occurs at the point of union of 

 the transvere with the longitudinal trunk as also in the latter between 

 the transverse commissures. 



Two kinds of cells occur in the ganglion. The commissures are 

 connected by two pairs of longitudinal fibers and these intersections 

 are also ganglionic. Further details are promised in the final paper. 



C. L. H. 



The Use of Corrosive Sublimate as a Fixing Medium.^ 



Dr. Schaper warmly recommends Zenker's solution (a mixture of 

 bichromate of potassium, sulphate of soda and acetic acid with the 

 mercuric chloride) on account of its superior permeability and uni- 

 form action. In this, however, as in all other methods of sublimate 

 impregnation much embarrassment grows out of the fact that the mer- 

 curic salt tends to crystalize out within the tissue. While it is true 

 that the salt can be removed by iodine tincture yet the injurious ef- 

 fects of this fluid are always apparent even if the dilute fluid is used 

 for the shortest time possible. The injury is least when the crystals 

 are dissolved in the sections. However, the author points out that 

 their presence during paraffin imbedding causes serious injury to the 

 tissues. Specimens from which the sublimate crystals were removed 

 before imbedding proved well preserved, while a portion of the same 

 piece not so treated but imbedded in the same way was seriously in- 

 jured. The author supposes that the injury is not due to the presence 

 of the crystals directly as the elasticity of the tissue accomodates to 

 the foreign bodies, but when they are present during paraffin imbed- 

 ding the tissues lose their elasticity and the presence of the crystals 

 then operates to produce large cavities. 



It would seem to the reviewer better to avoid a method in which 

 such distortions are possible and to seek to prevent the crystal depo- 

 sition or restrict the use of sublimate to tissues in which cytological 

 structures are of secondary importance. Nevertheless he has secured 

 beautiful preparations of the central nervous system with sublimate in 

 which no crystaline deposit was formed at any time. c. l. h. 



' Alfred Schaper. Zur Sublimatfixation. Anat. Anzeiger. XII. 17, 1897. 



