246 HELEN DEAN KING. 



eine besondere Austrittsoffnung in die Peritonealhohle hergestellt 

 wird." 



According to Brandt, the ovarian egg of Rana is surrounded 

 by membranes whose origin he describes as follows : " Die 

 Follikel des Ovariums durften dadurch entstehen, dass die einzel- 

 nen sich vergrossernden Eianlagen von den benachbarten, sich 

 proliferirenden und abplattenden Elementen, sowie von den 

 Bindegewebselementen der Ovarialwandung umwachsen warden. " 

 These membranes are said to form the follicle sacs that are found 

 on the inner wall of the ovary after the eggs have passed into the 

 body cavity, but no mention is made of their later history. Dur- 

 ing his investigations, Brandt carefully injected colored fluids 

 into the ovary just after the eggs had been laid and found that 

 none of the fluid ever came through the walls of the follicle sacs. 

 He was thus able to show conclusively that there is no commu- 

 nication between the cavity of the ovary and the body cavity 

 through the walls of the follicle sacs. The latter have but the 



o 



one opening which leads outward into the body cavity. 



The investigations recorded in the present paper were made to 

 supplement the work of Brandt and others with a more detailed 

 description of the origin and fate of the follicle sacs of the am- 

 phibian ovary. Observations were made on three different 

 amphibians, Bufo lentiginosus, Rana palustris and Hyla. The 

 general description and the drawings (made with a camera 

 lucida) are taken entirely from Bnfo lentiginosus as I had a much 

 more complete series of this species. As the relatively few 

 stages of Rana and Hyla at my command confirmed the results 

 obtained on Bnfo in every respect, a separate description of the 

 follicle sacs in these two amphibians seemed unnecessary and is, 

 therefore, omitted. In preparing the material for study, small 

 portions of the ovary were fixed in corrosive-acetic, and then 

 stained on the slide either with iron-haematoxylin, or with a mix- 

 ture of Lyon's blue and borax carmine, as described in a previous 

 paper (King, 2). 



The ovary of Bnfo lentiginosus consists of several distinct com- 

 partments, agreeing in this respect with the ovary of various 

 species of frogs, according to the observations of Rathke, Lere- 

 boullet, Brandt and Schultze(s). The walls of these compart- 



