C. Crowther and H. E. Woodman 447 



It will be observed that with the exception of Sheep 1 in Period I 

 a positive nitrogen balance was maintained throughout. An interesting 

 correlation between the amounts of nitrogen consumed and the amounts 

 of nitrogen retained becomes evident if the data be rearranged in order 

 of increasing nitrogen consumption as set out in the following table : 



It will be seen that with the exception of Sheep 2, Period V, in 

 each case as the nitrogen consumption was increased the nitrogen 

 retention increased up to a certain point and then fell, the maximum 

 retention being recorded by each sheep in Period II (Hay + Palm 

 Kernel Cakes), in which roughly 17 gms. of nitrogen (= 106 gms. crude 

 protein) per head per day were consumed. This amount is equivalent 

 to 2-4 kg. crude protein per 1000 kg. live-weight, the nutritive ratio of 

 the ration being practically 1:6. The estimated "starch equivalent" 

 of the ration moreover was highest in this period (cf. p. 432). 



The lower retention in Periods I and IV is doubtless due to the 

 smaller consumption of nitrogenous matter, but it is not clear why less 

 nitrogen should have been retained in Periods III, V and VI. It is 

 hoped that further studies now in progress will throw light on this 

 point. 



REFERENCES. 



1. G. KtJHN et al. Amlbl. f. d. landio. Vereine Kngr. Sachsen, 1872, p. 137. 



2. E. Wolff et al. Landw. Jahrbiicher, v. 1876, p. 513. 



3. E. Weiniger. Landw. Versuchsstat., lxxii. 1910, p. 143. 



4. F. Barnstein, Landw. Versuchsstat., liv. 1900, p. 327. 



5. A. Morgen et al. Landw. Versuchsstat., lxxxv. 1914, p. 1. 



6. O. Kellner. Die Erndhrung der landw. Nviztiere, 1 Auf., p. 32. 



7. T. Pfeiffer. Jottrn.f. Landw. xxxi. 221; xxxtn. 149; xxxiv. 425. Zeits. J. 



physiol. Chem. x. 170, 561 ; xi. 1. 



8. T. Katayama. Landw. Versuchsstat. lxix. 1908, p. 321. 



9. A. Morgen et al. Landw. Versuchsstat. Lxxr. 1909, p. 1; lxxiii. 1910, p. 285; 



Lxxv. 1911, p. 265. 



{Received February 22nd, 1917.) 



