1917] ANIMAL PRODUCTION. 269 



slight flavor of lime. Similar results were secured in tests in 1915. In 1915 

 eggs packed in boxes in powdered peat and in common salt evaporated consid- 

 erably in 6.5 months' stoi'age, and the flavor was only fairly good. 



[Feeding experiments with beef cattle, brood sows, and work horses] 

 {Minnesota Sta., Rpt. Duluth Substa., 1916, pp. 7-9, 10, 11).— In 1916 young 

 beef animals were pastured without extra feed on range a part of which was 

 tame grass pasture. Three of the yearlings were on grass 49 days and seven 

 127 days. They made an average daily gain of 1.59 lbs. per head. 



Brood sows on pasture from June to September, inclusive, slightly increased 

 in weight when receiving ^ lb. of grain per 100 lbs. live weight, whereas before 

 and after the pa.sture period they consumed 1 lb. of grain per 100 lbs. live weight. 



Six work horses were pastured at night on stump-land pasture from June to 

 August, inclusive. During the three months the night pasture resulted in a 

 saving of 12 lbs. of hay and 1 lb. of grain per head daily. 



In a test of a self-feeder for pigs on a ration of tankage shorts, ground barley, 

 and skim milk, 13 pigs made an average daily gain from June 15 to October 15 

 of 118 lbs. per head at cost for grain of $4.69 and a profit of $11.80, 



A feeding trial with a litter of fall pigs is also noted. 



The theory of correlation as applied to farm-survey data on fattening 

 baby beef, H. R. Tolley {U. S. Dept. Agr. Bui. 50 Jt {1911), pp. i^).— This bul- 

 letin gives the results of an experiment in applying the theory of correlation 

 to the study of some of the data obtained by the Office of Farm Management 

 in a survey of corn-belt farms upon which baby beef was being fattened for 

 market, the details of which have already been noted (E. S. R., 35, p. 668). 

 The factors here considered are the profit or loss per head, the weight, value 

 per 100 lbs., value of feed consumed per head, cost at weaning time, and date 

 of sale. Coefficients of correlation were computed and tabulated for every 

 pair of these factors and used as a measuje of the relationship existing between 

 them. 



The author concludes that "data such as those obtained by farm manage- 

 ment surveys can be analyzed very thoroughly by the use of the correlation 

 coefficients. It is generally known before the analysis is attempted which 

 factors are causal and which resultant, and consequently there should be very 

 little difiiculty in interpreting the coefficients correctly. The coefficients of 

 net correlation afford a very good means of determining the net effect of each 

 of several factors bearing upon a result, or of eliminating the effect of other 

 factors when it is desired to find the true relationship existing between any 

 two. 



"Although it is not possible to give a definite concrete meaning to correlation 

 coefl!icients, they are very concise relative measures of the degree of relationship 

 existing between the factors being studied. They therefore give the investigator 

 a single index which will show what, by the ordinary tabular method, it takes 

 a whole table to show. While properly constructed tables will show whether 

 or not any relationship exists between factors, it is a difficult matter to determine 

 which of two causes, say, has the greater effect on the result, and it is im- 

 possible, without a large number of records and a great amount of sorting and 

 tabulation, to separate all the factors being considered in a study and find the 

 effect that each one would have had if the others had not been present, or if 

 they had been constant throughout the investigation. 



" If the gross coefficients of correlation between every pair of factors have 

 been determined, it is possible to find these relationships by simply substituting 

 in the formula for determining a net coefficient from the gross coefficients, with- 

 out any further reference to the records themselves. This method should be 

 especially useful if only a limited number of records or observations are 



