2o6 
THOMPSON YATES LABORATORIES REPORT 
of the Wallerian degeneration in all the fibres of the distal pieces of the root. Aseptic healing 
took place in all the instances quoted. 
Experiment i. Animal killed on the loth day. Examination ot the Vllth segment of the 
spinal cord. Very few apparently normal cells were met with, and these were chiefly small ones. 
The slightest change noticed, and whicJi was also that which occurred most frequently, consisted 
in a loss of any definite arrangement of the blue coloured Nissl bodies. Fine blue granules were 
uniformly disseminated throughout the cell bodies, and hence the cells presented the appearance 
of being less deeply stained than normal. In cells of this type the nucleus remains practically 
normal. 
In other cells the alteration was more pronounced ; the nucleus was smaller than normal ; 
it had lost its well-defined margin and became wavy in outline and was surrounded by a reddish 
zone from which chromapithic bodies were absent. This is a stage of chromatolysis. In a few 
cells the nucleus had lost its central position and become eccentric. 
In rare cases there was an invasion of a disintegrating process of chromatolysis from the 
periphery. 
Experiment 2. Animal killed on the 14th day : the cord presented the same general 
appearance as in the former case, the change however being a little more advanced. A typically 
altered cell had the following appearance. The nucleus which was central had lost its definite 
outline and its membrane was not visible, the nuclear chromatin had not the ordinary net-like 
appearance, but had the appearance of an irregular homogeneous star-like body. A nucleolus was 
invisible, but several darkly blue stained particles might represent it. Round the nucleus was a 
space which contained fewer chromatic masses than the periphery ; hence it looked reddish, but 
was dotted with a fine dusty blue substance. 
The peripheral blue had entirely lost its characteristic striated arrangement, and was 
represented by a diffuse blue mass on wliich many darker points appeared (see Plate). 
A small minority of cells showed the process of chromatolysis beginning at the periphery, 
and in a few the nucleus assumed a distinct eccentric position. 
Experiment 3. Animal killed on the 14th day. The changes found were similar in all 
respects to those detailed above. 
Examination of the Oculomotorius and Facialis Nuclei after Division of the 
Corresponding Nerve Trunk 
A detailed account of the results obtained is given below. I wish to emphasize that so far 
as my own observations are concerned, the resulting changes are much less marked than those 
described as occurring after section of a spinal anterior root. This is especially so in the case of 
the IlIrd nerve where the changes are altogetlier very slight. 
At an earlier period of this investigation, in the Report to the British Association, 1897, 
I stated tliat I was unable to find in these cells changes corresponding to the descriptions of other 
observers. 
I am still or this opinion as regards the degree of change met witii, but further experience, 
