PHYSIOLOGY OF THE OVIDUCT PL5 
In regard to the time taken by the egg in passing through the 
isthmus our observations are far from agreeing with the state- 
ments on this point in the literature. Taking the mean of all 
available data 0.6 of an hour is found to cover the time during 
which the egg is in the isthmus. All our observations agree well 
amongst themselves, and we are convinced that this figure is 
substantially correct for the breed of fowls here used (Barred 
Plymouth Rocks). This is a much shorter time than earlier 
workers have estimated. Thus Gadow’ says: ‘‘Im Isthmus 
soll das Ei ungefahr 3 Stunden lang verweilen.”’ Lillie’ gives 
the same estimate on the authority of Kolliker. Patterson? who 
has published most recently on this matter, while reducing some- 
what the time for passage through the isthmus, still gives a value 
considerably higher than that found in the work of this laboratory. 
His statement is as follows (loc. cit., p. 105): ‘‘The writer finds 
that in a hen kept under normal conditions, the egg traverses 
the entire length of the oviduct in about twenty-two hours. 
The time occupied in the different portions of the oviduct is as 
follows: Glandular portion, three hours; isthmus, two to three 
hours; uterus and laying sixteen to seventeen hours.”’ With all 
parts of this statement except that relating to the isthmus our 
results are in entire agreement. At an early stage of the studies 
in this laboratory on the physiology of the oviduct we were of 
the same opinion as Patterson as to the time taken in passing 
through the isthmus. More extended observations, covering 
a fairly wide range of conditions has convinced us that, as 
already stated, the egg normally takes less than one hour in 
passing through the isthmus. It is, of course, possible that 
there are breed differences in respect to the time the egg stays in 
the isthmus, and that Barred Plymouth Rocks are strikingly 
exceptional in this regard but this hardly seems probable. It is 
more likely that the estimate of earlier workers has been somewhat 
too large. 
7 Gadow, H.., loc. cit., p. 872. 
SNOGaGtt 
9 Patterson, J. T., Journal of Morphology, vol. 21, pp. 101-134, 1910. 
