252 Proceedings of the Royal Physical Society. 
progress, but the assimilated matter is being utilised, the 
ratio is less than unity. During the phase of mature life 
the ratios vary indeed from hour to hour, but the mean of the 
A! wt 
K’ Dae 
phase of growth the mean of the ratios (which have also 
periodic variations) is greater than unity. 
It must be carefully noticed that there may be for equal 
periods of time more anabolism in the mature organism than 
in one that is growing, but in all animals the general 
various ratios etc., equals unity, while during the 
BES ASU ; : 
ratio 4 will be greater during adolescence than during 
maturity. Moreover, as the rates of assimilation and dis- 
assimilation fluctuate greatly at different times, in contrast- 
ing different phases, the mean of the ratios for corresponding 
periods must be considered. 
4, Minot’s CONCLUSIONS AS TO GROWTH.—In this connec- 
tion it is interesting to notice, partly by way of illustration, 
Prof. C. S. Minot’s investigations on growth. With admir- 
able patience he has framed from observations on guinea-pigs 
the most exhaustive series of statistics on growth which we 
at present possess. His observations, though chiefly on 
guinea-pigs, were not restricted to these, and his results are 
striking. He finds that “the rate of growth of the guinea- 
pig declines almost from the moment of birth onward, and 
there is no such thing in the history of the guinea-pig as a 
distinction between the period of development and the 
period of decline. It is one steady decline when we measure 
the actual growth in this proper, exact manner. The same 
law holds true of man, of chickens, of rabbits, of dogs, of 
ferrets, of all of which animals I possess sufficient statistics 
to speak with confidence.” There is, he says, a progressive 
loss in power of growth, “a steady loss of vitality.” 
“Whereas the first ten per cent. of addition is made in a 
time a little exceeding two days, the twenty-fifth addition of 
ten per cent. is made in a period of nearly eighty-eight days.” 
Moreover, Minot also finds that as age increases the ratio of 
protoplasm to nucleus in the cells increases, and so he 
reaches the somewhat unexpected conclusion that “ proto 
