EIGHTH” ANNUAL REPORT. 119 
and in this paper is a preliminary study designed to outline the 
subject. I have refrained in it from unnecessary details, stating 
as briefly as possible only the lesions bearing directly on the dis- 
ease. No constant or significant alterations have been found in 
the general viscera, and for this reason they have not been in- 
cluded in this study, though a complete examination was made in 
each instance. 
No gross lesions of the central nervous tissues were found in 
any case except one, where meningeal exudate was present, a 
point confirmed by the microscopic examination. 
Since this study is intended only as a preliminary outline and 
not as a finished article—most of the cases not having been care- 
fully observed clinically—the pathological studies have been but 
fragmentary. In the time at my disposal for the preparation of 
this article it was manifestly impossible for me to carefully study 
each of the cases, hence segments were selected from the cords, 
with the full understanding that an examination of each seg- 
ment, of each posterior root ganglion, and of many of the periph- 
eral nerve fibers, as well as the entire encephalon, would be 
necessary were the study designed to be a finished one; such 
minute examinations would seem wasted on material, most of 
which has been casually observed by the keepers of the animals 
and occasionally by the veterinarian. The observations are sub- 
ject to the assumption that the general arrangement of the tracts 
and fibers is the same in these animals as in man, an assumption 
probably inaccurate. I am indebted for most of the gross patho- 
logical observations to Dr. W. Reid Blair of the Park. 
Technic.—Previous experience in the study of the spinal cords 
of the smaller animals has taught me that the removal of the 
cord from its bony canal while the tissue was perfectly fresh fre- 
quently resulted in formation of serious artefacts, consequently I 
removed the entire spinal column in the first four of the following 
cases, immersing it for 48 hours in a 5-per-cent. solution of forma- 
lin, after which the bones were carefully cut away, exposing the 
cord more immediately to the action of the formalin. Tissues for 
general tissue changes were then transferred to graded alcohol, 
embedded in paraffin, cut and mounted in the usual manner and 
stained chiefly with hzmatoxylon and eosin, also with Van 
Gieson’s picro-acid fuchsin. Sections stained with the Neisl blue 
were also prepared in the same general manner. 
Segments intended for detection of degenerated fibers and 
tracts, were hardened and prepared after the method of Marchii 
or by the Busch modification of the same method. 
