195 



often be seen marked by a narrow neck of protoplasm, wlucb 

 eitber reunite to form one cell, or else divide into two, wbieb 

 remain permanently distinct. Another method of division is 

 for a cell to flatten itself out into a disc, from the surface of 

 which arises a kind of mound or elevation, containing a 

 nucleus, which finally separates. The same phenomena 

 were easily seen in the frog's blood, and also in human blood, 

 when kept at a temperature of 35° to 40° C. 



Tendons. — Giiterbock (' Med. Centralblatt.,' January 

 15th) has repeated the observations of Ranvieron the tendons 

 of youug animals, and has come to the following conclusions : 

 — The fissures which are found between the fibrillar bundles 

 of the tendons contain chains of staff'-shaped nucleated cells, 

 which may be called connective tissue corpuscles, and Avhich 

 are less numerous in the tendons of adults than in those of 

 young animals. The tendons are so rich in cells as to be 

 little inferior to cartilage in this respect. These chains of 

 cells pass uninterruptedly into rows of cartilage cells, where 

 the tendons are inserted into cartilage. 



Muscular Fibre. — Professor Krause has contributed to 

 the ' Zeitschrift fiir Biologic ' a paper on the structure of 

 striated muscular fibre, in which he controverts the views of 

 Hensen, which have lately attracted much attention. Accord- 

 ing to the latter observer, each transverse stria or disc of 

 doubly refracting substance is divided by a disc of less highly 

 refracting substance, which he calls the " median disc." This 

 appearance is regarded by Krause as a misinterpretation of 

 the appearances, and due, at least in part, to the action of 

 water. The median disc he believes to be merely the central 

 portion of the dark or doubly refracting substance, rendered 

 paler by the action of water, and also brought into contrast 

 by the greater distinctness given to the planes of contact of 

 the dark and light substances. Krause has also seen the deli- 

 cate line crossing the middle of the light substance, described 

 by Hensen, and described also long ago by Dr. Carpenter, from 

 Lealand's preparations (' Human Physiology,' -ith edition, 

 p. 296). We are unable now to give a fuller account of this 

 important paper. 



Lymphatics of the Eye. — Schwalbe contributes to 

 Schultze's 'Archiv' (vol. vi, part i, 1870) an elaborate paper 

 on the lymphatic spaces connected with the eye. He confines 

 himself in the present memoir to those of the posterior divi- 

 sion of the eyeball. The posterior lymphatic system is defined 

 as including the perivascular spaces of the retina, the peri- 

 choroid space with its efferent channels, and, finally, a lym- 

 phatic space between the outer and inner sheaths of the optic 



