Journal of Comparative Neurology. 



by this author for his hypothesis, that the protoplasmic processes have 

 a predilection to group themselves around the blood vessels and that 

 they are connected with connective tissue cells, have not been veri- 

 fied either by Cajal himself nor by Kolliker, van Gehuchten, Lenhos- 

 sek, Retzius. Schafer, etc. 



6. The extraordinary length of some protoplasmic processes 

 (pyramidal cells of the cerebrum, Purkinje's cells) and the abundance 

 of their lateral and basal processes seems to be dependent upon the 

 number of nervous terminal dendrids, whose impulses they must re- 

 ceive. 



Continuity versus Contiguity of Nerve Cells. 1 



Professor A. S. Dogiel challenges the 

 doctrine of strict anatomical independence 

 of neurons. In the retina he finds not 

 only anastomoses of the fine branchlets of 

 the dendrids, but also a direct anastomosis 

 of the cells themselves by means of a thick 

 fibre. We reproduce in diagrammatic 

 form one of his illustrations of the latter 

 type. 



The author concludes that in the re- 

 tina, at least, the nerve cells constitute a 

 colony of individuals all intimately bound 

 together by means of their protoplasmic 

 processes. 



Fig. 7. Nerve cells from the inner ganglionic layer 

 of the retina of man. Methyl hlue preparation, a, an 

 axis-cylinder process; b, protoplasmic processes: c, a pro- 

 cess which unites the bodies of the two cells, from which 

 pass out lateral branches, V. 



Intra-Cranial Pressure. 2 



The animals employed were cats or dogs. After a description of 

 the methods of research, the following table of results is given : 



i. The normal intra-cranial pressure scarcely ever exceeds 10 

 mm. Hg. 



'Dogiel, A. S. Zur Frage iiber das Verhalten der Nervenzellen zu einan- 

 der. Archhi f. Anat. u. Phys. Anat. Ab. 5-6, 1893. 



2 Hill, Leonard. On Intracranial Pressure. Preliminary Note. Proc. 

 Roy. Soc, LV, 331. 



