1036 Journal of Agricultural Research vol. vi.No. 25 



per cent of the trials to induce egg formation around artificial yolks were 

 failures suggest that the sex organs must be and must remain in absolute 

 functional condition until the egg is completed. 



Loeb (9) showed that the mammalian uterus responds to a mechanical 

 stimulus by the formation of the maternal placenta during a definite 

 period after ovulation. He finds that during this period the uterus is 

 sensitized by the internal secretion of the corpus luteum. We may con- 

 ceive that the specific state of the oviduct in the fowl which renders it 

 capable of responding to mechanical stimulation, be it yolk or foreign 

 body, is associated with some quantitative or qualitative difference in 

 the internal secretion of the ovary. While from the data given above 

 it is possible that it is due to some postovulation change in the ovary, 

 this seems improbable. We know that in many and probably in most 

 cases in normal-egg production the duct responds to the first yolk of a 

 series ovulated. This response occurs immediately after ovulation — that 

 is, there is not sufficient time for a change in the internal secretion of 

 the ovary occurring at or after ovulation to affect the state of the duct. 



An observation made some time ago also has a bearing on this point. 

 A bird which had laid three days earlier was selected for an abdominal 

 operation. She was accidentally killed with an overdose of ether just 

 after the incision was made. The oviduct did not contain an egg, but 

 the funnel was in active motion when first observed. It responded 

 quickly and sharply when stimulated by pinching with the forceps. The 

 albumen region also responded to this stimulus by strong peristaltic 

 movements. A 10-cm. piece from the albumen-secreting region of this 

 very active duct was cut open lengthwise and spread out flat with the 

 glandular surface exposed in a warm damp chamber moistened with salt 

 solution. Small bits of cork were scattered on the surface in order to 

 study ciliary motion. The ciliary activity continued for 1% hours. At 

 the end of this time it was noted that a very thin film of albumen was 

 visible on the surface of the mucosa. In this case an isolated piece of 

 oviduct responded to mechanical stimulation by the secretion of a very 

 small amount of albumen. This duct had not been sensitized by an 

 immediately preceding ovulation. The last ovulation had taken place 

 four days before the bird was killed. The active movements of the 

 funnel when the body cavity was opened suggested that an ovulation 

 was about to take place. Either the duct had remained in a condition 

 capable of a secretory response for four days or it had again come into 

 such a condition with the maturing of another yolk. 



The above-described experimental work and the observations on the 

 conditions under which dwarf eggs are produced indicates that mechani- 

 cal stimulation of the oviduct results in the formation of egg envelopes 

 only under a particular condition of the duct which seems to be associ- 

 ated with the maturing of yolks by the ovary. The sensitization of 

 duct, if this is the proper explanation of the phenomena observed, 



