1238 Proceedings of Royal Society of Edinburgh. 
these are not provided with nerves. The nerve-fibres grow out 
from the cells and pursue their several paths with the most 
unerring exactitude towards the elements with which they 
ultimately become connected. The fibres which form the efferent 
nerves grow out from the nerve-cells in the brain and cord ; the 
fibres of the afferent nerves arise from the ganglion cells outside 
and grow into the brain and cord so as to establish their con- 
nections with the central nervous axis. This may seem a small 
point, and yet it forms the embryological basis of our modern 
conception of the manner in which the nervous system is built up, 
and also of the manner in which its different units or neurons are 
connected. 
But it would be wrong, even in a short notice such as this of 
necessity is, to omit to refer to the useful work performed by 
Professor His in the department of topographical anatomy. 
During the last thirty or forty years our ideas in regard to the 
form and relations of the different parts of the human body have 
undergone a complete revolution. Professor His was one of the 
leading pioneers in bringing about this change. 
It is not so long ago that the anatomist derived all his 
information in regard to the topography of the body from 
dissection alone. No other method was followed ; and when, as 
in these times, it was not combined with measures for the 
preservation of the form of the parts under observation, the- 
amount of information it yielded was limited, and not unfrequently 
misleading. Sections of the frozen body, introduced by Pirogoff, 
carried out to such perfection by Braune, and now practised by 
teachers all over the world, led to a great advance in every 
department of topographical work. It then became possible to 
check the results obtained by dissection, and correct many erroneous 
impressions for which the latter method was responsible. 
The next step was taken by Professor His, who hardened the 
viscera in situ by prolonged injection of chromic salts ; and it is 
no too much to say that the models which he prepared from 
these specimens, and which are at present used wherever the 
study of anatomy is pursued, have had a profound effect on 
anatomical thought and teaching. Recently the method of Pro- 
fessor His has been brought to a state bordering on perfection by 
