70 EXPERIMENT STATION EECOED. [Vol, 35 



made use of, two depend on pasture and soiling crops, and one depends very 

 largely on pasture. 



Report of the first Jersey sires' futurity test of the Aroostook Jersey 

 Breeders' Association, R. Pearl (Maine Sta. Bui. 2Ji7 (1916), pp. 31-52). — It is 

 Stated that the idea underlying the inauguration of the sires' futurity test 

 was that the surest indication that anyone can have of the breeding worth or 

 value of an animal lies in the performance of its progeny. The first sires' 

 futurity test of the Aroostook Jersey Breeders' Association was held at 

 Aroostook Farm, Presque Isle, Maine, November 15, 1915, under the auspices 

 of the station. Rules and methods of conducting the test are given, together 

 with the results in milk and fat production in the 1915 test. 



Finding' the prepotent sire, J. M. Ho^^!;B (Jour. Heredity, 7 (1916), No. Jf, 

 pp. 173-178). — Tlie author concludes from the study of the Guernsey advanced 

 register that " marked prepotency is limited to a comparatively few animals ; 

 strongly prepotent sires usually belong to prepotent families or strains ; pre- 

 potency is probably enhanced ])y inbreeding ; iirepotency may become a valuable 

 aid to intelligent selection in breeding for greater production." 



The causes of the beginning of milk secretion, H. IMollgaaed (Mwlkeritid., 

 28 (1915), No. 7, pp. 121-139, fig. Jf).— As a result of his studies the author con- 

 cludes that in the preparatory growth of the milk gland in young female 

 animals during their first pregnancy chemical substances are secreted in the 

 ovary. The lacteal gland during pregnancy secretes during its latter half of 

 development certain chemical substances, apart from the progeny itself, which 

 go into the mother's blood. The beginning of milk secretion is intimately 

 connected with the expulsion of the progeny, and possibly separates chemical 

 compounds which emanate from the placenta. The influence of the hypophysis 

 is deemed of considerable indirect importance in the secretion of milk. 



The preservation of milk samples for investigational purposes, J. Till- 

 MANs, A. Splittgerber, and H. Riffaet (Ztschr. Untcrsuch. Nahr. u. Genussmtl., 

 27 (1914), ^0. 12, pp. 893-901; abs. in Hyg. Rimdschnu, 26 (1916), No. 1, p. 21).— 

 Various methods of preserving milk samples are described. 



Report of the committee on standard methods for the bacterial examina- 

 tion of milk, M. P. Ravenel et al. (Amcr. Jour. Pub. Health, 5 (1915), No. 12, 

 pp. 1261, 1262). — Methods for the bacterial examination of milk as adopted by 

 a committee of the American Public Health Association in September, 1915, 

 are outlined. 



Counting bacteria by means of the microscope, R. S. BxiEEo and J. D. Brew 

 (New York State Sta. Tech. Bui. J^9 (1916), pp. 3-31, pis. 2, figs. 5).— This is a 

 continuation of work previously noted (E. S. R., 31, p. 78). The present bul- 

 letin reviews and discusses the technique involved in counting bacteria in milk 

 and other substances by means of a microscope, giving at the same time the 

 results of studies which have been made in order to determine the sources and 

 the amounts of the errors in counts made in this way. 



" The results obtained from the examination of samples of milk collected in 

 clean test tubes containing preservatives indicate that just as accurate counts 

 of the number of bacteria present can be made from such samples as can be 

 made if the samples are collected in sterile tubes and iced. Under certain con- 

 ditions this method of collecting samples may become a great convenience. 

 Capillary pipettes have been found to be more satisfactory for the measure- 

 ment of 0.01 cc. quantities of milk than standardized wire loops. Faulty 

 calibration of pipettes has been found to be a serious cause of error. Allow- 

 ance must be made for the adhesion of a certain quantity of milk to the pipette 

 if accuracy of measurement is to be secured. 



