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Proressorn HumpHry made a communication on certain 
depressions in the parietal bones of the skull of an Orang and 
in Man. He showed the skull of an Orang which had been 
lately presented to the Anatomical Museum by Mr Vores of 
Caius College, in which these depressions exist. They look as 
if the bone had been indented on either side of the sagittal suture 
by the pressure of the finger, the surface being quite smooth 
and the edges of the depressions bevelled. There was no corre- 
sponding alteration in the contour of the interior, the bones 
being simply thinned at the part. He had not met with a 
similar abnormity in any other instance of an animal, but had 
seen it a few times in man, and showed two skulls from the 
Museum in which it was present, the outer table of the skull 
being depressed in a considerable area of each parietal bone, 
and the skull at the parts beg quite thin. The remaining 
pone-structure was healthy, and there was no reason to attribute 
the condition to disease of any kind or to accident. The 
appearance and the symmetrical position of the depressions 
were against both these suppositions. Neither did it seem 
possible to account for the depressions by any kind of pressure 
that was likely to occur. Professor Humphry thought they 
were probably due to a deficiency in the early formative pro- 
cesses in consequence of which the bone had not been produced 
of proper thickness at these parts, but he could not in the least 
explain why such deficiency should occur. 
A paper was read by C. Yuus, B.A, late of St John’s, 
Fellow of Magdalen College, Oxford, “On the Mechanism of 
opening and closing the Eustachian Tube.” In the first part of 
this paper the arguments in favour of the Eustachian tube being 
normally closed were reviewed, in consequence of the contrary 
view having been again revived by Dr Cleland, and some new 
ones added. The chief point brought forward, however, was 
the undoubted voluntary power possessed by Mr Yule over his 
