ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 239 



To discover what the experiment teaches concerning certain general 

 principles the records of all cows for the first three months are cona- 

 piled and the results tabulated and briefly discussed. The records of 

 all the cows for the month of May though voluminous are published in 

 full to facilitate a study of variations as between individuals. Follow- 

 ing this are given full records of one of the cows for the entire experi- 

 ment in order to afford data for a study in individual variations from 

 day to day and throughout an extended period. All the tables are drawn 

 upon for data bearing upon the constitution of milks produced under 

 varying conditions as to animals and time, but not disturbed by feed. 

 Last are certain miscellaneous data of interest in the same connection. 



VARIATIONS IN MILK. 



Table 1. Total yield of milk in pounds per m.onth, morning aud 

 evening. 



JOCK DOLLY EVA JANET r^^?-^Z. 



Pietertje 

 a. m. p. m. a. m. p. m. a. m. p. m. a. m. p. m. a. m. p. m. 



May 445.5 871.6 338.7 277.1 306.1 271.3 S74.6 304.0 583.4 482.9 



June 301.4 266.4 335.8 277.0 269.0 234.3 360.7 309.3 491.6 428.3 



July 44.6 58.5 292.6 273.4 222.1 213.0 299.4 279.8 390.7 372.2 



As would be expected the largest yield is at the morning milking. 

 The only exception is that of Jock in July at the close of hrsr milking 

 period. Why conditions should be reversed in her case is a mystery 

 that is not cleared up by the closest study of her daily performance. 

 The greatest difference in favor of the morning milking of any cow and 

 for any month is 100.3 pounds, or 18 per cent, of Lady Pietertje for May. 



The question next arising is whether or not the excess of the morn- 

 ing's milking over that of the evening corresponds exactly to the differ- 

 ence in the length of periods which are to each other as 13 to 11. To throw 

 light upon this question the following table is constructed: 



