644 TRANSACTIONS OF SECTION I. 
MONDAY, AUGUST 30. 
The following Papers and Report were read :-— 
1. Preliminary Note on the Origin and Function of the Postero-Septal 
Tract. By W. Paar May, M.D., D.Sc. 
Aided by numerous microscopical specimens and lantern slides, Dr. Page 
May gave a description of a descending tract discovered by him some 
five years before in the brain stem and spinal cord of the monkey. For 
this nerve path he suggests the name of the postero-septal tract. He 
demonstrated its presence in several monkeys and dogs and traced its origin 
and course as presented chiefly by two methods, viz., secondary degeneration 
according to the Law of Waller, with subsequent staining by osmic acid, 
and also by retrograde chromatolysis arising in the nerve cells which give 
origin to the fibres of the tract following upon section of these fibres. He 
traced the postero-septal tract from its origin in the joint region of the 
optic thalamus and corpora quadrigemina along chiefly the mesial fillet 
into the posterior columns of the spinal cord, where it lies symmetrically 
on either side in close contact with the posterior septum and descends 
slightly diminishing to the lower thoracic region, where it rapidly ter- 
minates in the 10th and 11th thoracic segments. 
A series of somewhat detailed experiments with a view to elicit the 
function of this tract has only so far definitely shown that it is not con- 
cerned with the pyramidal or voluntary motor path, nor with any obvious 
vasomotor processes of the spleen, kidney, and other important organs as 
examined by the plethysmographic method. As, however, the postero- 
septal tract is relatively of fair size, its functions must be somewhat 
important, and is receiving further investigation. 
2. Degenerative Changes, with especial reference to the Brain, following 
Lesions of the Spinal Cord. By W. Paar May, M.D., D.Sc. 
Dr. Page May demonstrated with microscopic specimens and lantern 
slides changes which occur in certain cells and groups of cells, more particu- 
larly in the brain subsequent to various lesions in the spinal cord and other 
parts of the central nervous system. These changes were not only shown 
in the red nucleus, deiters nucleus, and various other groups of cells which 
give origin to cerebro-spinal fibres and spino-cerebral fibres, but in a 
joint work by him and Dr. Gordon Holmes had served to delimit the true 
motor area in the cerebral cortex of the cat, dog, lemur, monkey, chim- 
panzee, and man. The cerebral cortex in each series of cases was cut in 
serial section, and according to the period of time allowed to elapse after 
the lesion, the absence of certain cells or chromatolytic changes in these cells 
made it easy to map out, in addition to the motor area, the actual cells 
themselves, which give origin to cortico-spinal fibres. The bearing of this 
knowledge on clinical work was briefly indicated. 
The method of investigation chosen is free from numerous possible 
fallacies which occur in the stimulation and ablation methods frequently 
adopted in the past, and which have given many discordant results in the 
hands of numerous observers. It showed definitely that the cerebral motor 
area in man and the higher mammals is pre-central, not at all post-central, 
and in addition gave many important details. Some of these results are in 
disagreement with statements in regard to the cortical motor area as given 
even in many recent textbooks, but in the main confirm, and by an entirely 
different process, the results of Grinbaum and Sherrington in their classical 
work on the chimpanzeé. 
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