448 Drs. S. M. Copeman and H. W. Hake. [June 19, 
always food, and killed at once, the mice with transplanted tumours showed 
an average greater proportion of physiologically active hydrochloric acid in 
the gastric contents, with a less variation between the extremes, than was the 
case with the normal mice. 
It is only right to state that in the case of the mice with tumours referred 
to in Table A, although they were fed and killed as above stated, the 
stomachs were not sent to us at once, but kept, in an ice safe in glass tubes 
with cotton wool stoppers, for periods varying froma few days to a few weeks ; 
the stomachs of the normal mice, however, killed as controls, were sent in a 
fresh condition. It was obvious that this procedure was not altogether 
satisfactory and in all the other experiments we arranged to have the 
stomachs sent to us perfectly fresh, so that there was the least possible delay 
between the time of killing and the commencement of their analysis. It 
must be further stated, however, that the above experiments are as perfectly 
reliable as the later experiments with fresh stomachs, which tended in all 
respects to confirm these first results. 
(2) Experiments made on Mice and Rats with Special Reference to Time of 
Digestion. 
It was obvious, however, that a definite period of digestion would be likely 
to give a more strictly comparable series of results, and we selected in the 
first instance a period of one hour. The mice, whether normal or with 
transplanted tumours, were put in cages overnight without food, were fed 
next morning and killed one hour after feeding.* Series 6 to 10 were 
conducted in this manner and a summary of results is given in Table B. The 
mice in this case, as in the previous series, were over twelve months old. The 
results obtained again appeared to emphasise, even more strongly, the fact 
that there was an average increase in the secretion of hydrochloric acid in the 
stomachs of mice with transplanted tumours as compared with normal mice 
during a period of digestion of one hour. 
Thus, as against an average of 0°1488 per cent. in normal mice, we found an 
average of 0°1627 per cent. in mice with non-ulcerated tumours and of 
0:2100 per cent. in mice with ulcerated tumours. 
But a difficulty in these, as also in the previous experiments, was that 
although in the whole of the 10 series, with two exceptions only, a more or 
less considerable increase of hydrochloric acid was indicated in the case of the 
mice with transplanted tumours, the actual percentages of hydrochloric acid 
in each class varied nevertheless somewhat largely inter se, and more especially 
in the normal stomachs. 
* The food consisted of bread soaked in water, oats, and canary seed. 
