294 GEORGE W. BARTELMEZ 



assuming that the funnel is inactive while an egg is in the 'uterus.' 

 The evidence for this is that in a dozen or more cases studied in 

 which the first egg was in the uterus, the funnel was not found 

 about the second follicle and no peristaltic movements were 

 observed in it. This is supported by the fact that in the hen, 

 where there are normally several large follicles, Patterson ('10) 

 found the funnel inactive while there was an egg in the uterus. 

 As has been said above, three follicles occasionally mature in 

 the pigeon. In two such cases the following conditions were 

 found. The first egg was laid normally and that night the bird 

 was killed. The second egg was in the oviduct, but in addition 

 a third one was found just ruptured from its follicle and in the 

 base of the funnel. This indicates that the funnel remains active 

 for some time after ovulation, but considering that there is no 

 record of a pigeon having laid more than two eggs at a sitting, 

 it seems probable that after an egg enters the 'uterus,' an anti- 

 peristalsis ejects any other that may be in the oviduct. In one 

 of the cases referred to, the orientation of the follicle in the funnel 

 probably did not take over an hour. 



Another important factor in the orientation of the ovum in 

 the oviduct is the way in which the follicle ruptures. The stigma, 

 it will be remembered, extends in the long axis along the free 

 pole of the follicle and so its cloacal end lies at the base of the 

 funnel where this passes over into the glandular part of the oviduct. 

 It will readily be seen that the cloacal end of the stigma is there- 

 fore the one part of the follicle where the pressure from within 

 is not balanced by any pressure from without. Now when the 

 various pressures become great enough, the rupture begins at 

 the cloacal end of the stigma (a statement based on the study 

 of over two hundred recently ruptured follicles); usually before 

 the tear has extended along more than 10 mm. of the stigma, 

 the ovum has been squeezed out of the follicle, mainly by the 

 rapidly contracting wall of the latter, and lies at the base of the 

 funnel. The escape of the ovum through an opening one-half 

 its own diameter — I have watched this several tim^s — indicates 

 the elasticity of the extremely delicate vitelline membrane (chor- 

 ion) and the flexibility of the ovum. In spite of this distortion 



