134 Proceedings of the Royal Society of Edinburgh. [Sess. 
2. The cells forming the more distal segments of the limbs possess in 
the majority of cases a greater absorptive power than those forming the 
more proximal, and consequently experience the greatest liability to death 
by surfeit. 
It is well to examine in detail the collateral evidence in support of the 
first of these statements. If it be established, the second, in the light 
of the definitely ascertained anatomical facts, is inevitably true. 
Scattered through the records of the experiments upon castrated 
animals, there is evidence of the favourable type of their somatic 
nutrition. 
Thus, in the experiment upon fowls (Observation B 1) the capons were 
found to be very fat, and weighed 2800 and 2650 grammes, compared with 
weights of 1955 and 2105 grammes attained by the cocks used as controls. 
But indeed, with regard to capons, it is unnecessary to go to the laboratory 
for such collateral evidence, for it is because of this very fact that castration 
does determine a greater body growth that poultry breeders capon their 
cockerels. A rather instructive point in this connection is, that many of 
the so-called capons sold by poultry dealers are in reality young cocks and 
hens subjected to forced feeding with the aid of cramming machines. 
Similar evidence exists with regard to other castrated animals, and this 
condition of what may be called hyperanabolism persists for some time, 
but as the animals age it passes off. The reason for this is not difficult to 
understand, but its demonstration would involve a long digression. It is 
merely mentioned here to point out that it is not to be expected that old 
castrated animals will be heavier than old entire animals. 
But though this collateral evidence is satisfactory so far as it goes, it 
does not equal in conclusive force the results that might be obtained from 
direct experiment. Of course the fact that the forced feeding of poultry 
produces capon-like birds is in one sense a direct experiment, and artificial 
experiments on any other lines than that of forced feeding are exceedingly 
difficult to devise. But nature herself sometimes carries out what are in 
essence perfect physiological experiments, and there is one which con- 
clusively shows that rapid growth of cartilage and its attendant rapid bone 
formation are directly stimulated by the existence of a favourable 
environment. 
The experiment is this : The human embryo is carried for nine months 
within the uterus of the mother, and during this period, as in after-life, 
different human beings are subjected to different conditions of nutritive 
supply. Sometimes the foetus is over-nourished and grows to such an 
extent that it cannot be born alive. One such foetus that was examined 
