STRUCTURAL ALTERATTONS IN NERVE CELLS 209 
In most instances the changes in my preparations have not advanced beyond the first 
Stage. Owing to the large size of the cells, this is specially well seen in preparations of the 
spinal cord from the first series of experiments. The stage of commencing chromatolysis was 
reached in a few. 
In the case of the facial nucleus, again, the changes noticed belong chiefly to the stage of 
reaction, the more extreme changes of the nature of degeneration, which from the descriptions 
and figures of other writers would appear to be very common, were only rarely represented in 
my preparations. The same is also true with regard to the oculomotorius nucleus — cells showing 
signs of the stage of degeneration were practically absent, thus contrasting markedly with the 
figures published by Flatau, who also divided the Ilird nerve inter-cranially. 
The condition of the nucleus in the Monkey is remarkable. At the end of 28 days there 
was no trace of any of the changes just enumerated, but a distinct diminution in the number of 
the cells in the side of the lesion. 
In the upper part of the nucleus the marked connective tissue reaction which is present 
would account for this disappearance of cells, but the rest of the nucleus is free from any such 
invasion. 
Is this alteration comparable to that described by Forel and Darkschewitsch (/.c) in the 
case of the facial and hypoglossal nerves ? If so, it has certainly occurred at a very early date ; 
Ballet has however, as early as 37 days after the section of the sciatic nerve, found a marked 
diminution in number of the cells of the anterior horns in the corresponding spinal segment, the 
remainder showing the normal structure. 
The view adopted by this observer was that the atrophy and disappearance represented 
the final result of the process of chromatolysis. 
It is difficult in transverse sections to recognize the various groups which compose the 
oculomotorius nuclei, but the sections show clearly that the most dorsal (superior) group of cells 
was least affected, and it is probably this region which gives origin to fibres of both Ilird nerve 
(Gudden), and hence might a priori be expected to suffer least. 
In contrast to the results of this experiment is the observation on the condition of the 
same nucleus in the Human subject. The perfectly normal appearance in this case supports the 
view put forward by V. Gehuchten at the recent Congress in Moscow, that atrophy of the 
nucleus of origin after division of the nerve trunk is not yet an established fact. 
In conclusion I beg to express my obligation and thanks to Professor Sherrington for 
his kindness and help, and especially for valuable suggestions in connection with the former 
part of this paper. My best thanks are also due to Professor Bovce, who has throughout aided 
me by advice and criticism. 
SUMMARY. Part II 
1. Distinct and easily recognizable changes in nearly all the cells of a segment of the 
spinal cord are found on the side of the lesion after section of an anterior root. 
2. Similar but less marked changes follow division of the facial nerve, and still less distinct 
alteration after division of the oculomotorius nerve. 
