SCIENTIFIC SUMMARY. 
331 
PHYSIOLOGY. 
The Secretion of the Gastric Glands. — Professor Heidenhain succeeded in 
separating a considerable portion of the fundus of the stomach in a dog 
from its connection with the rest of the organ, and forming it into a blind 
sac communicating with the exterior of the body. This enabled him to 
collect the secretion of the gastric glands unmixed with that of the pyloric 
glands, and uncontaminated by the saliva and other liquids which pass 
down the oesophagus. The secretion is a clear, strongly acid liquid, con- 
taining an unexpectedly small amount of mucus, and an average of 0-45 per 
cent, of solid matter, partly organic, partly inorganic, the former consisting 
mainly of pepsine. The average acidity of the liquid is equivalent to 052 
per cent, of hydrochloric acid, which is far higher than that of the mixed 
gastric juice, free from saliva, examined by Bidder and Schmidt. Itichet, 
from observations on the juice of a man with a gastric fistula, found that 
when fresh it contained only hydrochloric acid, while when kept for a time 
it developed an organic acid, probably sarcolactic. No such acid was 
observed to be produced in the secretion obtained from the dog. It was 
found that the introduction of nutritious food into the stomach induced 
active secretion in from fifteen to thirty minutes, and this continued until 
the stomach had completely emptied itself. But if indigestible substances 
were introduced no secretion flowed from the sac for upwards of an hour. 
Water was then given to the animal, and secretion commenced, but only 
lasted an hour and a half. From these and other experiments, Professor 
Heidenhain concludes that mechanical stimulation of the stomach excites 
secretion only at the point of contact ; general activity of the glandular 
apparatus requiring absorption for its production. If the composition of the 
secreted liquid be examined at regular intervals during the digestive 
process, its acidity is found to remain pretty uniform, but the proportion of 
pepsine contained in it undergoes a peculiar and orderly series of variations. 
During the second hour it sinks rapidly to a minimum ; towards the fourth 
or fifth hour it rises again to a point generally higher than at first, and 
remains at or near this point for a considerable time. These variations are 
quite independent of the amount of pepsine actually contained in the glands 
which is known to sink steadily. The secreting surface can pour out a 
liquid very rich in pepsine at a time when its poverty in this substance is 
most strongly marked. No definite conclusion can at present be arrived at 
as to the cause of this phenomenon. {Pfliiger's Archiv., vol. xix. ; Academy f 
April 26, 1878.) 
ZOOLOGY. 
The Bovidce. — M. A. Sanson has communicated to the French Academy 
of Sciences a note on the results of his researches upon the fossil or ancient 
remains of Bovidse and their relationships to existing forms, which are of 
some interest. 
He finds that the Aurochs of Cuvier, Bos urus of Bojanus, B. prisons, 
Allen, B. latifrons , Harlan, and B. antiquus , Leidy, are all Bisons which 
