HISTOLOGY OF THE OVIDUCT OF THE; DOMESTIC H^N. 397 



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the principal reasons for this view was the fact that the 

 fibers of the membrane swell up and expand when treated with 

 alkali and contract when immersed in acetic acid. In this action 

 they appeared to them to resemble smooth muscle fibers. Nasse 

 ('62) and Blasius ('67) pointed out the incorrectness of this 

 view. 



Landois ('65) further believed that the mamillary layer of 

 the shell consisted of the uterine glands which were cast oiT 

 with each egg and then regenerated. He says (p. 4) "Nach 

 meinen Untersuchung der Entwickelungsgeschichte der Schale 

 im Eileiter kann hieriiber kein Zweifel mehr obwalten. Es 

 sind die Driisen der Uterinschleimhaut, welche sich auf der 

 Faserschichte der Eischale angesetzt haben." This theory was 

 an attempt to bring the avian uterus into agreement with the 

 known action of the mammalian uterus. Blasius C^7) among 

 others brought forward considerable evidence to refute this 

 theory and to show that all the shell layers were secreted by the 

 oviduct. 



Nathusius ('68) believed that the egg membranes were or- 

 ganic tissues and that the shell and its membranes were derived 

 from an elaboration of the yolk membranes in which the cal- 

 careous matter was deposited. Agassiz, Milne-Edwards, 

 BHasius and others recorded observations which disproved this 

 theory. 



The most important of the older works on the histology of 

 the avian oviduct is that of Sacchi ('87). She studied in con- 

 siderable detail the histology of the oviduct in both the active 

 and inactive states. Many of the results of the present study 

 are not in accord with Sacchi's findings. These will be dis- 

 cussed at the proper places in the following paper. Loos ('81) 

 has also contributed a most excellent paper on the structure of 

 the avian and amphibian oviduct. He was the first to point 

 out the tubular nature of the albumen glands in certain birds 

 (crow) and showed there that these had definite openings into 

 the lumen of the duct. 



Giacomini ('93) has studied the histology of the oviduct in 

 various birds, including the domestic hen. In certain respects 

 this work is more thorough than any which precedes it. Quite 

 recently Sturm fio) has given an account of some of the more 



