274 EXPEKIMENT STATION EECOED. 



hog as it lias on tliat collected from the horse. . . . Semen from different 

 males varies greatly in its vitality under laboratory conditions. Tliis differ- 

 ence is sometimes so noticeable as to indicate the probability of poor breeding 

 qualities." 



To determine the vitality of sperm cells in the female, sows were killed at 

 varying lengths of time after service. Of the 19 sows bred and killed the 

 sperm cells were found dead in SO per cent of the cases where a period of 

 16 hours or more had elapsed. In one case the live cells were found after a 

 lapse of 22i hours, and iu 2 cases after a lapse of more than 40 hours. 

 Vitality tests with the sperm of horses showed it to be very short-lived either in 

 the mare or under abnormal conditions. 



To learn of the effect of continuous service, a heavy draft stallion was used 

 once each day. The number of sperm cells present in the semen in his first 

 service was 1.31.750 per cubic millimeter, and liA'e cells were found 9.5 hours 

 after service when kept at from 31 to 35° C After the ninth service there were 

 only 5,840 si:)erm cells per cubic millimeter, and the vitality of the cells was 

 less than one-half as compared with those of the first cells. Other experiments 

 for 11 days' and 18 days' consecutive service showed that the vitality was re- 

 duced from the first to the last service. Chemical analyses of the sperm cells 

 are given. 



Experiments were also made to determine the time of the rupture of the 

 Graflian follicles and the vitality of the ova in sows. " If the hog was killed 

 early in the period of heat the follicles showed perfect and imruptured, while 

 those from hogs killed a few hours later showed the follicles ruptured. A few 

 sows were killed when not in heat, and in none of these were the follicles found 

 well developed or in condition to liberate the ovum, neither did they show any 

 signs of the recent escape of the ovum from the organ. Variations from the 

 normal no doubt do occur, but it is safe to assume that in the great majority 

 of cases the follicles do not rupture before 30 hours after the period of heat 

 begins." Whenever sows were bred out of heat no results were obtained unless 

 it occurred within 1 dny. Post-mortem examinations after breeding out of 

 heat indiciite that the ovum and sperm cells soon lose their physiological ac- 

 tivity after they become separated from the ovary and testes. 



" The vitality of the reproductive cells of the hog is only a few hours. In 

 most cases the ovum appears to lose its power of being fertilized within 48 

 hours, and the sperm cell does not appear to possess much, if any, greater 

 vitality. . . . The ovum (in hogs) is not liberated from the ovary until the 

 last pnrt of the period of heat." 



Artificial insemination, L. L. Lewis (Oklahoma 8ta. Bui. 93, pp. o-lS, 

 figs. 5). — A revised edition of a bulletin previously noted (E. S. R., 17, p. 1193), 

 with a bi'ief report of experiments which are more fully noted in Bulletin 96 

 (see page 273). 



Is the control of embryonic development a practical problem? C. R. 

 Stockard (Ahs. in Science, n. ser., 35 {1912), No. 907, p. 788). — This is an 

 abstract of a paper read before the American Philosophical Society, 1911, which 

 discusses the factors which cause embryonic deformities in man and animals. 

 These may be distinguished as those caused by the embryo developing in an 

 unfavorable environment, and those in which the germ cells of both parents 

 may have been defective. 



The results of exjierinients with guinea pigs have shown that when put into a 

 state of chronic alcoholism and mate<l together or with normal individuals, 

 the resulting offspring were greatly affected, showing that the paternal germ 

 cells are affected by the alcohol and produce abnormal offspring. It is sug- 



