256 Artijicial Insemination 



of the secretions of the accessory sexual glands (natural sperm). In this 

 medium there can be no question of sterilization and, what is particularly 

 important, the seminal cells coming into contact with the secretions of 

 the accessory sexual glands change their biological properties — acquiring 

 a maximum of energy and dying in a comparatively short time (a few 

 hours). Some methods of elucidating the nature of factors determining 

 these properties are already mapped out and the solution of this problem, 

 we are entitled to think, is only a question of time. 



There remain a few words to be said on the development of the 

 technical side of the work. In view of certain inconveniences connected 

 with the sterilization of the sponge collecting the sperm when tlie male 

 covers the female, I have substituted for the 2 % solution of sodium 

 carbonate a solution of spirits of wine (60-65 %) in which the sponge is 

 kept about an hour, then thoroughly cleansed with sterilized water, and 

 finally washed several times (being repeatedly squeezed out in the press) 

 with a sterilizing physiological solution of kitclien salt, or a 10 % 

 solution of refined sugar. This method of sterilization has been used in 

 practical work by veterinary surgeons since 1911. Before this innovation 

 was recommended for actual use, it underwent a number of suitable 

 tests and investigations in the laboratory and on the experimental 

 station in Askania-Nova which have shown its usefulness. 



LITERATURE. 



Heape. The Artificial Insomination of Mammals {Proc. Roy. Soc. 61, 1897). 



■ The Artificial Insemination of Mares {Veterinarian, 1898). 



IvANOFF. De la F^condation Artificielle chez les Mammiferes {Arch, des Sciences Biol. 

 12, 1907, St Petersburg). 



De la Kcondation Art. clicz los Animaux domestiques {Arch, de Vet. Sci. 1910, 



St Petersburg). 



Die Kunstiiche Befnichiung der Haustiere, Hannover, 1912. 



Beschreibung von Ilybriden, etc. {Zeitschr. f. Induktive Abslammungs- und 



Vererbungslehre, 16, 1916). 

 Marshall. The Physiology of Reprodiiction, 2nd ed., London, 1922. 

 MabsH;\ll and Croslani). Sterility in Marcs, etc. {Journ. of Board of Agric. 24, 1918). 

 Wolf. The Survival of Motility in Mammalian Spermatozoa {Journ. of Agric. Sci. 



11, 1921). 



{Received June '21st, 1922.) 



