PHYSIOLOGY OF THE OVIDUCT 415 



of peristaltic movements of the intestines and oviduct, together 

 with the chance of being lodged in some undisturbed position, 

 and partly also upon the general physiological tone of the indi- 

 vidual and the consequent power of absorption from the general 

 peritoneal surface. 



From his study of "the effect of variations in body position 

 and in gastrointestinal activity upon the degree and extent of 

 diffusion of benign and toxic substances when introduced intra- 

 peritoneally" and of "the influence of the degree of diffusion upon 

 the absorption of toxins" Yates ('08) concludes that: 



1. Intraperitoneal diffusion results from the operation of purely 

 physical forces abetted by physiological activities. 



2. The greatest attainable restriction of this diffusion must result 

 from the opposition of controllable physical force to the paths of greatest 

 extension and the inhibition of physiological activities. 



3. Under similar conditions the rate of absorption varies directly 

 with the extent of diffusion. 



Our observations on the absorption of eggs discharged into 

 the body cavity are in general agreement with Yates' experi- 

 mental results. 



When a bird is laying she is transforming a large amount 

 of material into egg substance. Gerhartz ('14) has recently 

 made accurate measurements of the energy contained in the 

 egg and of that utilized in the digestion and absorption of the 

 extra food and in converting body substance into egg substance. 

 With the laying of the egg all this energy is lost to the indi- 

 vidual. When the egg is deposited in the body cavity and 

 resorbed the energy contained in the egg, minus the energy re- 

 quired for the resorption, is retained by the individual. When 

 egg formation is stopped at ovulation, the ovulated yolk being 

 resorbed from the body cavity, not only is the energy contained 

 in the yolk saved to the individual but also the energy which 

 would have been contained in the egg envelopes and that which 

 would have been utilized in their elaboration. If the energy 

 consumed in the - resorption of yolks or eggs from the body 

 cavity is less than the energy contained in fully formed eggs, 



