1920] 



ANIMAL PRODUCTION. 



671 



place in the clmnued circle of big prices depeiuls very much upon the personal 

 skill and advertising art of the owner." 



A map is presented showing the decline in sheep breeding in different parts 

 of England. 



Further studies on the influence of humidity upon the strength and 

 elasticity of wool fiber, J. I. H.\iu)y (Jovr. A(jr. Research iU. S.], 19 {1920), 

 No. 2, pp. 55-62, fiijs. Jf). — Additional determinations of the mechanical prop- 

 erties of wool liber at the Wyoming Experiment Station are reported in con- 

 tinuation of work previously noted (E. S. R., 30, p. 774). Most of the observa- 

 tions were made on a set of four samples of different average diameters at 

 five relative humidities, vie, 40, 50, 60, 70, and 80 per cent. Observations on one 

 of the samples was made at 100 per cent humidity. 



The ultimate strength of both scoured and unsecured wool per unit of cross- 

 section area decreased irregularly as the humidity changed from 40 to 80 per 

 cent. The strength of unsecured wool then increased as the' saturation point 

 was reached, while the str(?ngth of scoured wool remained substantially un- 

 change<l. The elastic limit increased steadily until it reached a maximum at 

 80 per cent humidity and then declined abruptly. 



I Particularly in the case of the finer wools, the ultimate strength seemed to 

 vary as the diameter of a fiber, and not as the cross-section area (square of 

 the diameter). 

 Regulations of the Secretary of Agriculture under the United States 

 Warehouse Act of August 11, 1916, as amended July 24, 1919. — Regu- 

 lations for wool warehouses (C7. S. Dept. Agr., Off. Sec. Circ. 150 {1920), pp. 

 5/).— This publication includes the text of the United States Warehouse Act 

 and the regulations for wool warehouses promulgated June 18, 1920. 



Variations in farrow, with special reference to the birth weight of pigs, 

 W. J. Carmichael and J. B. Uice {Illinois Sta. Bui. 226 {1920), pp. 67-95, fig. 

 1). — The authors tabulate and discuss a large amount of data extracted from 

 the farrowing records of the university herd of swine from 1903 to 1916. Many 

 of the tables have the form of frequency distributions and correlation tables, 

 but averages and percentages are the only statistical determinations attempted. 

 The following table summarizes such of the records as arc grouped by 

 breeds, omitting the two litters of Hampshires: 



Relation of breed of hogs to gestation period, fertility, and birth weights. 



In the treatment of the mutual relation.ships of length of gestation, age of 

 sow, size of litter, birth weight, order of farrowing, sex ratio, and still births, 

 the records of all breeds and a few crossbred litters are combined. 



The average gestation period was 114.58 days. The length of gestation 

 seemed not to be influenced by the age of the sow. Litter size was not affected 

 by length of gestation, but sows under two years of age produced litters 



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