198 



book/ gives an account of some important observations on 

 migratory cells, whicb, thongli published before, have hardly 

 attracted sufficient attention in this country. He describes 

 as of normal occurrence in the deep layer (rete mucosum) of 

 the epidermis, in the corium, and in the subcutaneous con- 

 nective tissue certain cell forms having the following charac- 

 ters. They are round, oval, or irregular in shape, composed 

 of soft, brilliant protoplasma, with a more or less distinct 

 nucleus, readily stained by carmine, and agreeing generally 

 with the lymph or white blood-cells in form, size, and proper- 

 ties. Being generally met Avith in the vicinity of blood- 

 vessels, and differing in structure from the regular cells of 

 the part, Biesiadecki regards them as identical with the " mi- 

 gratory cells" first described by Kecklinghausen in the cornea, 

 and since then often observed in diseased parts (being, accord- 

 ing to other observers, extravasated white blood-cells). The 

 number of these cells met with depends very greatly upon 

 the vascularity or oedema of the skin, and they are enor- 

 mously increased, especially in the deep layers of the epi- 

 dermis, in certain pathological conditions. Such cells and 

 their migrations seem to have a more important place in 

 physiology and pathology than has yet been assigned them. 



Stomach.— K. Triitschel (' Med. Centralblatt,' Feb. 19th) 

 has examined the terminations of nerve-fibres in the mucous 

 membrane of the stomach of the frog. He finds in the sub- 

 mucous tissue a fine plexus of delicate fibres, in which cells 

 are here and there embedded. This is in direct relation with 

 nerve-brancheii, so that the whole must be regarded as a 

 nervous structure. Other nervous filaments, which are not 

 a part of this network, extend in the direction of the mucous 

 membrane, and dividing into smaller branches reach the 

 epithelial layer. In the mucous membrane itself is a layer of 

 large multipolar cells, connected with one another by pro- 

 cesses. These are also, without doubt, nervous structures. 

 From these, moreover, nerve-fibres arise, which reach the 

 epithelial layer, and there form a second plexus ; while a third 

 similar structure is described as lying immediately under the 

 epithelium. Certain oval, clubbed bodies, which are met 

 with between and among the cylindrical epithelial cells, are 

 regarded as the ultimate terminations of the nerves. The 

 evidence of the nervous character of these diflferent structures 

 rests principally on their coloration by chloride of gold and 

 osmic acid. 



Liver.— Hering, in an account of the liver, published in 

 the third part of Strieker's ' Handbook of Histology,' repeats 

 his important and now well-known observations on the 



