REPRODUCTION IN THE DOMESTIC FOWL. 1 99 



than antiperistalsis. C. J. Hick and J. W. Visher (9) have 

 lately analyzed the muscular movements which cause regurgita- 

 tion of the duodenal contents into the stomach and have found 

 that they are not antiperistaltic in character. The precise 

 nature of the movements of the oviduct which force an egg 

 backward can be more safely decided after they have been ob- 

 served or experimentally produced. An examination of the 

 cases discussed in the literature and described above give little 

 evidence that the oviduct glands are excited to pour out theii 

 secretion by an egg moving up the duct. If this were the case 

 a complete normal egg in the body cavity or in the upper part of 

 the oviduct or included within another egg would have a re- 

 versed set of egg envelopes surrounding the shell. That is, 

 around the shell would be an egg membrane. This membrane 

 might be separated from the shell by thin albumen since it has 

 been shown (14) that this albumen is formed in the isthmus 

 and uterus and taken into the egg through the egg membrane 

 probably by osmosis. Whether or not thin albumen can come 

 in after the thick albumen is covered by a completed shell is not 

 known. The egg normally comes to ics full weight before che 

 shell is very thick. Surrounding the egg membrane we would 

 then find a layer of thick albumen. This is not the case in 

 most eggs which have backed up the duct. The eggs found in 

 the body cavity and upper oviduct as a rule were in the same 

 condition as an egg from the lower part of the duct. In case 

 they were included or were becoming included in a second set of 

 egg envelopes these envelopes were in the same oder in the in- 

 cluding as in the included egg. That is, albumen, egg membrane 

 and shell. This indicates that the envelopes were formed during 

 a second passage down the duct. In this connection Hargatt 

 (8) says: "If it should be queried why such deposition might 

 not have taken place on the ascent of the egg by antiperistalsis 

 as well as during its later descent, it may suffice to admit that 

 perhaps it did occur. However, in case the return of the egg 

 up the oviduct took place soon after its original descent, the 

 glandular structure would be in a state of exhaustion and hence 

 capable of only slight discharge." However, it has been shown 

 in earlier investigations from this laboratory (2) that the passage 



