1226 REPORT—1 885. 
Dr. Struthers concluded by inviting the members to view these urns and bones, 
arranged in a gallery in one of the anatomical laboratories at Marischal College, 
and also a number of interesting skulls of various races of mankind, which he had 
placed there for the occasion. He also mentioned that Aberdeen University was 
now forming at King’s College a museum of archeology, which they hoped 
would represent the prehistoric remains of man in the north-east of Scotland. As 
convener of the committee on the movement, he stated that they would be glad 
to receive all such specimens found in the district. 
5. Some important Points of Comparison between the Chimpanzee and Man. 
By Professor D. J. CunnincHam. 
Professor Cunningham exhibited some plates of frozen sections of the chim- 
panzee, which brought out several important points of comparison between it and 
man. 
6. Abnormal and Arrested Development as an Indication of Evolutionary 
History. By J. G. Garson, M.D. 
Dr. Garson began by stating that, perhaps, the most fertile source of informa- 
tion regarding the history of man’s evolution is derived from a study of his em- 
bryological development. Another source from which much valuable information 
regarding the early history of our own specialisation, and that of other animals, 
might be gleaned, is Teratology, which had for its domain the consideration of 
abnormal conditions of development. Many of the conditions included under this 
branch are of a pathological nature, and due to the effects of disease; others, 
however, are not—such, for example, as an abnormal and unusual production of 
normal structures and cases of arrested development. To a consideration of some 
conditions occurring under one or other of these categories he called attention. 
The examples which he had selected had come more especially under his own 
observation. Persons are occasionally found with abnormal development of hair 
on their bodies. The type mammal was an animal whose body was covered with 
hair. Under certain circumstances hair may more or less disappear, according to 
the conditions under which an animal lives. In man it is only feebly developed, 
except on the head ; and in the cetacea or whales it has entirely disappeared, with 
the exception of a very few bristles near the mouth. Dr. Garson proceeded to ex- 
plain how universal development of hair takes place in man. In ordinary cases 
the hair-growing apparatus in the embryo remains stationary, instead of keeping 
pace with the growth and development of the other organs of the body, with the 
result that no hairy covering such as is found in other mammals is present, but 
only short rudimentary hairs appear at intervals. But in some exceptional cases 
this stationary condition of the hair follicles does not occur, and they go on 
actively developing with the rest of the body, with the result that a hairy cover- 
ing is produced. ‘The hairless condition now normal in man has evidently been 
gradually acquired through a long period of time, as such a change could not take 
place rapidly and become such a stable condition as it is found to be otherwise. 
Abnormal development of fingers occurs sometimes in man, but must be classed 
entirely apart from such forms of abnormality as had been considered in the hair- 
growth, Supernumerary digits occurring in animals with a less number of digits 
than five indicated evolutionary changes in some cases, but in others were due to 
the same cause as their appearance in man. 
In arrested development the abnormal organ or portion of the body, instead 
of going through the various stages it usually does till it arrives at the condition 
it normally assumed in the group of animals in which it occurs, stops short at one 
or other stages. The stage at which it stops may correspond to that which is 
normal in a lower grade of animal life, and so gives direct evidence that the 
higher forms of animal life, such as man, pass through and beyond the stages at 
which the lower stop. It must not be forgotten also that in some respects an 
