DR. PETTIGREW ON THE CIRCULATION. 
G59 
One well-marked example came under my notice some time 
ago. In it, the foetus survived the natural term of pregnancy, 
and was enormous in bulk. As in cases of death of the pre¬ 
mature foetus, so in these cases the foetus may be mummified 
and retained entire, or it may putrefy and be gradually dis¬ 
charged. 
Dr. Keiller said that, although he had had some experience 
in delivering cats, and watching how kittens managed to get 
into the world, he had never had occasion to deliver a cow. 
He, however, knew that it was of no very infrequent occurrence 
for cows to have a missed labour, and that an unexpelled 
calf was frequently found, on killing a cow not known to have 
been pregnant, the calf being discovered in the uterus sur¬ 
rounded by a thick coating of lymph, or it might be, as in 
extra-uterine pregnancies, in the abdominal cavity, or par¬ 
tially expelled through the intestines. Dr. Duncan's 
mummified calf he considered an extremely interesting 
specimen. 
Dr. Hammond mentioned the fact that, in Forfarshire, the 
cattle which were impregnated during the cattle plague almost 
invariably aborted .—Edinburgh Medical Journal. 
DR. PETTIGREW ON THE CIRCULATION. 
In his eighth lecture on “The Physiology of the Circu¬ 
lation in Plants, in the Lower Animals, and in Man/' 
Dr. Pettigrew explained at considerable length the intimate 
relation which exists between the lungs and heart—the 
lungs circulating air and the heart blood. The lungs, he 
remarked, in their most rudimentary form, are mere sacs, 
walled off at an early period from the alimentary canal. 
They retain within certain limits the peculiar rhythmic 
movements which characterise the intestines. He compared 
the lungs to the hollow viscera as a class. In the water newt 
the lungs consist of a pair of elongated sacs, which have no 
laminae or folds in their interior. In the frog internal ridges . 
make their appearance, these increasing their respiratory or 
aerating surface. In the crocodile and turtle the ridges 
multiply and divide the interior of the lungs into cells; the 
differentiation going on in the lungs of birds and of mammals 
until those structures present a honeycomb appearance. By 
this means the aerating surface is enormously augmented. 
The lungs of serpents maintain their original tubular form, 
each terminating in an air-sac. The lungs of birds communi- 
