SECTIONAL TRANSACTIONS.—I. 459 
on Prof. A. Thomson’s theory of uterine absorption : technique of procedure estab- 
lishing vaginal absorptive capacity. 
The nature of vaginal secretions in the human female : chemical compounds formed 
by vaginal secretions: bearing of their nature on contraceptive technique : research 
desiderata. 
Muscular reactions of the non-pregnant uterus: discovery of and clinical verifi- 
cation of previously unsuspected cervical mobility in the human female: comments 
and criticisms of laboratory work on animals from which others have drawn deductions 
- without taking into account certain conditions essential to a successful experiment : 
some confirmatory data from medical practice. 
Dr. C. P. Buacker.—The Role of Genetics in the Future of Preventive 
Medicine. 
Profound differences of opinion exist among experienced no less than among lay 
people as to the relative influences of heredity and environment in determining human 
type. These differences are attributable to prejudice no less than to ignorance. 
Philosophie, religious, familial and political prejudices are considered. 
The general scope of our ignorance is defined. It is argued that this can be much 
reduced by disseminating an interest in pedigree study. If everybody carefully 
studied and impartially compiled their family histories to-day, there would be available 
for future generations an abundance of material utilisable for scientific purposes that 
would enlighten us as to the réle of genetics in preventive medicine. 
Prof. EK. P. Carucart, F.R.S—Man Values or Family Coefficients. 
Prof. A. V. Hitt, F.R.S.—The Recent Revolution in Muscular Physiology. 
Up to the end of 1926 current theories of muscular contraction were expressed in 
terms of lactic acid and of the energy provided by its formation from glycogen. The 
discovery of creatine-phosphoriec acid at the beginning of 1927 brought the subject 
to a new stage which reached its climax in the discovery by Lundsgaard in 1930 
_ that muscles may be so treated with iodo-acetic acid that they contract apparently 
normally but with no lactic acid formation at all. The present view is that the 
immediate chemical change in an excited muscle is the breakdown of creatine- 
phosphoric acid, this being followed immediately by the reformation of the latter at 
the expense of energy liberated by lactic acid formation, and later by the oxidative 
restoration of the lactic acid to glycogen. 
The new facts require a readjustment and re-statement of the conclusions from 
older work. They do not, however, as is sometimes asserted, upset it all. Most of 
_ the experimental facts and of the conclusions from them, particularly in relation to 
_ the recovery process, are independent of the precise mechanism involved. The present 
_ position is critically examined, particularly in relation to the case of muscular 
exercise in man. 
_ Prof. C. Heymans.—The Aortic and Carotid Sinus Nerves in the Regulation 
of Circulation and Respiration. 
Prof. J. Barcrorr, F.R.8.—The Limits placed by Altitude to Physical 
; Hzercise. 
The work of Italian researchers has shown that man can live at an atmospheric 
_ pressure of about 110 mm. Hg if he breathes, not air, but oxygen. At that pressure 
he can do little or no work. Recent researches by Barcroft, Douglas Kendal and 
Margaria have, however, shown that at 170 mm. pressure breathing oxygen, man can 
‘Step up 1,000 feet in an hour. As the work consisted of stepping on to a box, it was 
incidental that he stepped down as often as he stepped up. One hundred and seventy 
millimetres is a much lower pressure than that of the top of Everest. Therefore it 
follows that, given a supply of oxygen into the respiratory passages, the feat of 
climbing at the highest altitudes on the earth’s surface is not impossible, and, apart 
from unknown difiiculties in the terrain, the problem of climbing Everest is less one 
_ for the mountaineer than for the engineer. Not the engineer in general, but a 
