418 SCIENCE PROGRESS 



quantities of the foods under trial and the results obtained were 

 briefly as follows : 



Tot il quantity . 

 Starch equivalent (per cent.) 

 Total starch equivalent . 

 „ increase (14 cattle) 

 Increase per head per day 



These figures are so remarkable that with the object of 

 ascertaining their suitability for comparison they have been 

 subjected to careful examination. 



Scrutiny of the increase shows that the individual increases 

 are quite as good as can be expected. There are no notable 

 deviations. It may be mentioned that the cattle were fed as 

 six lots, each experiment being thus carried out in duplicate and 

 the fact that the results of the two series agree remarkably well 

 is evidence of trustworthiness. The probable error of the 

 gain has been calculated from Wood's figure of 14 per cent, 

 as the probable error of a single animal and are given below. 

 The actual probable error in these experiments appears to 

 be in the neighbourhood of 11 or 12 per cent, for a single 

 animal, so that the probable errors of the amounts gained are at 

 least not greater than those given. It may be noted that they 

 are small compared with the difference in the average daily 

 gain. They indicate for instance a 15 to 1 chance that the 

 daily gain of the linseed cake lot was at least 10 per cent, 

 greater than that of the coconut cake lot. 



Lot I. Lot II. Lot III. 



Linseed cake. Coconut cake. Wheat bran. 



Starch value of basal ration . . 1C35 10*35 10*35 



„ „ additional ration . 2*90 3" 18 2'02 



Daily gain (lb.) .... 2*27 ± '085 1-91 ±"07 2*02 ± "075 



The total starch values and the relative efficiencies of the 

 three rations are : 



Lot I. Lot II. Lot III. 



Linseed cake. Coconut cake. Wheat bran. 



Starch value of total daily ration . . . I3'25 I3"53 12*37 



Assumed necessary for maintenance . . 60 6*o 6'o 



Starch value available for live weight increase . 7*25 7*53 637 



Do. as percentage of ration No. 1 100 "<03*9 87*9 



Average daily gain as percentage of Lot I. . 100 84*1 89*0 



In order to arrive at something which will represent approxi- 

 mately the starch value available for gain, the figure representing 



