362 SECTIONAL TRANSACTIONS.—H, I. 
Examples of (1) archaic magic; (2) traditional folk-lore; (3) fairy 
beliefs. 
The Scottish witch was a repository of all kinds of beliefs, which leading 
questions at the trials occasionally made into a diabolical system. She was 
probably imaginative. Under suffering or torture she would confess to 
anything suggested to her. There is no real historic evidence for a witch- 
cult in Scotland. 
SECTION. I.—PHYSIOLOGY. 
Thursday, September 6. 
Symposium on Some recent advances in the physiology and pathology of 
the blood (10.0) :— 
Prof. J. Barcrort, C.B.E., F.R.S.—Respiratory function of blood in 
the foetus. 
The foetus presents the problem of an organism which is outgrowing its 
organisation for supply. This is true, among other things, of the supply of 
oxygen. The blood emerging from the uterus becomes progressively 
darker throughout pregnancy, which means a continuous drop in the 
pressure at which the oxygen is presented to the foetal blood in the placenta. 
The problem which confronts the organism is that of providing a sufh- 
cient pressure gradient between the maternal and fcetal blood. The solu- 
tion lies in a divergence of the dissociation curve of each blood from the 
normal. ‘That of the mother is displaced ‘ to the right’ and that of the 
foetus ‘ to the left ’—thus creating a gap, so that over a great part of the 
curve the feetal blood at a given oxygen pressure is about 25 per cent. more 
saturated than the maternal. The shift in the maternal curve is due to 
increased pH, that in the fcetal curve to a specific difference in the hemo- 
globin. 
The pressure at which the oxygen leaves the placenta in most animals 
is low ; it is further reduced before reaching the fcetal arteries by admixture 
of the umbilical blood with that from other veins. Consequently the 
embryo exists under anoxzemic conditions. 
Prof. L. S. P. Davipson.—WNutrition in relation to anemia. 
Within the past ten years an unparalleled advance in knowledge regarding 
the relationship of diet to blood formation has occurred, which has been the 
means of eliminating certain forms of anemia completely, of bringing 
under therapeutic control others which were incurable, and of directing 
attention to forms of anemia which had escaped notice. Previous to 1926 
the cause of pernicious anemia was unknown and treatment was so un- 
satisfactory that every patient died. ‘To-day we know that the essential 
cause lies in a failure of gastric secretion, so that the patient is unable to 
obtain from his food a principle which is essential for normal blood forma- 
tion. By the administration of liver, or extracts made therefrom, a sufferer 
from pernicious anzemia can now lead a nermal life. 
Of greater economic importance, in view of its extraordinary frequency, 
is the group of nutritional anzemias due to iron deficiency. Approximately 
50 per cent. of infants and adult women of the poorest classes are anzemic. 
The causes of this deficiency are now understood and accordingly can be 
