106 HENRY O. FEISS 
also in that disease, is at least partially due to the removal of 
inflammatory material, somewhat as in the conditions described 
above, where the exudate is dependent only on simple mechani- 
eal lesions, although part of the recovery in infantile paralysis 
may be related to cell changes which take place as a result of 
the expulsion or neutralization of specific toxines. As regards 
the later improvement in that disease, one is just as much in 
doubt as to which of the factors above mentioned is of greatest 
significance. 
It is plain, however, that the spontaneous recovery observed 
in infantile paralysis is perhaps an attribute less characteristic 
of the disease than of the anatomical structures which the dis- 
ease attacks. Whether it is a clean section, or a crushing lesion 
or an inflammation set up by some virus, there are certain suc- 
ceeding manifestations that seem to be common to all these ante- 
cedents, and these manifestations are exhibited with striking 
clearness simply because of the fact that in the central nervous 
system, a relatively small anatomical change affects an extremely 
large physiological sphere. 
PART 2. THE LOCALIZATION OF CENTERS IN THE LUMBO- 
SACRAL CORD 
Method of study and reasoning 
This part of the research is based on ten of the experiments. 
The study of data furnished by this material is summarized in 
tabular form (table 2) and each experiment is illustrated with a 
photograph, and a diagram based on the sketch made at the 
autopsy. In these diagrams only direct involvements due to 
the lesions are indicated. The degenerations were partly due 
to secondary operations, and are therefore best omitted, because 
under the circumstances they throw no light on the localization. 
in handling the data, each case is analyzed for itself and the 
inferences individually derived are collated according to the impor- 
tant clinical and physiological headings under which each was 
studied. The cord segments were numbered according to the 
roots, calling the root issuing beneath the last rib, the 13th. 
