TRANSACTIONS OF SECTION M. 665 
are to be explained by the presence of a protein impurity in the maltose used. 
With the aid of such yeasts it has been possible to show that even in plants 
such as the Potato, the Turnip, and the Nasturtium, which contain much starch 
in their leaves, maltose is never formed as a down-grade product of metabolism. 
Professor Armstrong took exception to Dr. Petrie’s conclusion that certain 
plants contained hydrogen cyanide in the free state: he regarded its presence 
as an impossibility and thought that probably in such cases the glucoside and 
enzyme were not separated so effectively as they are in most plants, so that 
they came together very readily on the cessation of metabolism. 
(i.) Feeding Statistics and Starch Equivalents. 
By Professor T. B. Woop, M.A., and G. Upyy Yuus, M.A. 
The authors have made a statistical study of the results of about 400 feeding 
trials collected and tabulated for the Highland and Agricultural Society by 
H. Ingle.1 The trials were all carried out with oxen or sheep in Great Britain 
before the year 1907. Some of them go back to the year 1839. Examination 
of the results has yielded the following conclusions :— 
1. When the diet of oxen or sheep is increased above maintenance require- 
ments the law of diminishing return asserts itself, and successive increases in 
the diet do not produce proportional increases in live weight. 
2. As the diet is increased above maintenance requirements a smaller propor- 
tion of each successive increase is converted into live weight, and consequently a 
larger proportion is lost as heat. 
3. When oxen or sheep in store condition are given a diet which supplies 
considerably more food than is required for maintenance the proportion of the 
excess of food above maintenance requirements which is converted into live 
weight continuously falls as fattening proceeds. 
4. From the above conclusions it follows that there is not a direct proportion- 
ality between the amount of food above maintenance requirements calculated as 
starch equivalent and the live-weight increase produced. 
5. The figures from which Kellner’s starch equivalents were calculated show a 
direct proportionality between the amount of starch equivalent above mainten- 
ance requirements and the live-weight increase produced. 
6. The discrepancy is explained by the fact that Kellner’s results were 
obtained by feeding animals in store condition for short periods during which 
they never approached what the butcher calls ripeness, whilst in the British 
trials the animals were fed for several months until they were ripe for the 
butcher. 
7. It is by no means rare to find individual oxen which on an average fatten- 
ing ration of 8-5 lb. of starch equivalent above maintenance requirements make 
daily live-weight increases as large as 3 lb. or as small as 1 lb. The former 
should give out 17,000 cal. per day, the latter 22,000 cal. per day, a difference of 
about 25 per cent. It should be possible to detect differences of this order by 
Ieasurements of skin temperature. 
(ii.) Fattening Capacity and Skin Temperature. 
By Professor T. B. Woop, M.A., and A. V. Hiun, M.A. 
The authors have measnred the skin temperatures of eighteen oxen which had 
been on a fattening diet for ten weeks at the Norfolk Agricultural Station. 
The measurements were made by means of a thermopile connected to a sensitive 
galvanometer. The following results were obtained: The average skin tem- 
perature of eight animals which had during the last three weeks made average 
daily increases in live weight of 2:7 per head was 69 scale divisions above air 
temperature. The average skin temperature of five animals which had during 
the same period increased less than ‘8 lb. per head per day was 78 scale divisions 
above air temperature. The good doers had cooler skins than the bad doers by 
nine scale divisions, which corresponds to approximately 3° C. 
1 Jour. High. and Agr. Soc., 1909, 1910. 
