2o8 THOMPSON YATES LABORATORIES REPORT 
nucleus tlie majority show a striated (stichochrome) arrangement of the chromopithic Nissl bodies, 
but in some these are arranged in the form of a network (arkyochrome), and in the case of cells 
belonging to this type I find it extremely difficult to say whether there is a distinct alteration in 
structure of the chromopithic masses. 
Experiment 2. Cat. Killed on the i6th day. Examination of the nucleus showed an 
appearance similar to that detailed above, if anything the alteration is less evident. 
Experiment 3. Monkey. Killed on the 28th day. The changes found in this case are of 
an entirely different nature, and consist of a distinct diminution in number of the cells throughout 
the whole length of the nucleus. I am unable to distinguish in any cells changes of a similar 
character to those described above. In transverse section the oculomotorius nucleus consists of a 
central and two lateral portions. The diminution in the number of the cells was found to affect 
the whole of one side with the exception of the upper dorsal group of cells. The central cells 
were symmetrical. 
In this case a proliferation of the connective tissue occurred which was limited to the most 
anterior part of the nucleus examined, it existed in 40 sections of 7/x each, and in that region 
almost entirely obliterated the lower part of the dorsal group of cells. 
Experiment 4. Man. Died 6 months after enucleation of one eyeball. The cells of the 
nucleus of the Ilird nerve appear throughout symmetrically arranged, and no difference in structure 
could be noticed on eitlier side of the nucleus. The cells in the middle of the nucleus, which are 
here larger and more numerous than in the extremities, stain deeply and show a well-defined 
distribution of the chromatic masses : — towards the limits of the nucleus in either direction the 
cells are smaller, and many of tliem on both sides possess an eccentric nucleus, while the Nissl 
bodies are very scanty, the cells in fact presenting appearances similar to those occurring in 
pathological conditions. 
The appearance does not however I think indicate any morbid state, possibly it is a 
post-mortem change, but the smaller cells of various parts of the nervous system often show 
similar features even when the tissue is quite fresh. Individual variation has also to be considered. 
In tlie case of the Monkey mentioned above, two distinct types of cells equally distributed were 
seen in the oculomotorius nucleus, one more spherical and lightly stained, the other polygonal 
and deeply stained, but the cells of this nucleus in a second Monkey were uniformly of the same 
type. 
REMARKS 
These results agree sufficiently with those of other observers to enable me to accept as a 
general law that in a cell loss of continuity of its axon is followed by definite structural changes. 
Marinesco {I.e.) divides the process into two stages. 
Reaction : — Characterized by a breaking up of the chromatic substance, the nucleus 
retaining its central position and the cell its normal contour. 
Degeneration : — Characterized by the occurrence of a chromatolysis which begins according 
to Marinesco and Nissl in the neighbourhood of the origin of the axis cylinder and spreads 
towards the dendrons. In this stage the nucleus assumes an eccentric position. 
