TRANSPORTATION OF EGG FROM OVARY TO SITE OF FERTILIZATION 199 



Some workers in artificial insemination use one type of diluent for ram 

 sperm, another for stallion sperm, and still another for bull sperm, etc. 



Artificial insemination of domestic animals and of the human female is 

 extensively used at present. It is both an art and a science. In the hands of 

 adequately prepared and understanding practitioners, it is highly successful. 

 The best results have been obtained from semen used within the first 24 

 hours after collection, although cows in the Argentine have been inseminated 

 with sperm sent from the United States seven days previously (Hartman, '39, 

 p. 685). 



F. Transportation of the Egg from the Ovary to the Site of Fertilization 



1. Definitions 



The transportation of the egg from the ovary to the oviduct is described 

 as external (peritoneal) migration of the egg, whereas transportation within 

 the confines of the female reproductive tract constitutes internal (oviducal) 

 migration. It follows from the information given above that the site of fer- 

 tiUzation determines the extent of egg migration. In those species where ex- 

 ternal fertilization of the egg is the habit, the egg must travel relatively long 

 distances from the ovary to the watery medium outside the female body. On 

 the other hand, in most species accustomed to internal fertilization, the latter 

 occurs generally in the upper region of the oviduct. Of course, in special 

 cases as in certain viviparous fishes, such as Gambusia affinis and Heterandria 

 formosa, fertilization occurs within the follicle of the ovary and migration of 

 the egg is not necessary. The other extreme of the latter condition is present 

 in such forms as the pipefishes. In the latter instance the female transfers the 

 eggs into the brood pouch of the male; here they are fertilized and the embryos 

 undergo development (fig. 106). 



2. Transportation of the Egg in Those Forms Where 



Fertilization Occurs in the Anterior Portion 



OF THE Oviduct 



a. Birds 



A classical example of the activities involved in transportation of the egg 

 from the ovary to the anterior part of the oviduct is to be found in the birds. 

 In the hen the enlarged funnel-shaped mouth of the oviduct or infundibulum 

 actually wraps itself around the discharged egg and engulfs it (fig. 31). Peri- 

 stalsis of the oviduct definitely aids this engulfing process. Two quotations 

 relative to the activities of the mouth of the oviduct during egg engulfment 

 are presented below. The first is from Patterson, '10, p. 107: 



Coste describes the infundibulum as actually embracing the ovum in its follicle 

 at the time of ovulation, and the writer [i.e., Patterson] has been able to confirm 

 his statement by several observations. If we examine the oviduct of a hen that is 

 laying daily, some time before the deposition of the egg, it will be found to be 



