Mark. — Lepidosteus. 



ABBREVIATIONS. 



cap. Head of villus. pd. Stalk of villus. 



c.-t. cp. Connective-tissue corpuscle. rx. Root of villus. 



/us. mat. Maturation spindle. st. ml. Villous layer of egg membrane. 



gran. Granulosa. th.fol. Membrana propria of theca folliculi. 



m pi), can. Micropylar canal. vac. Vacuole. 



m pi), cl. Micropylar cell. vit. Vitellus. 



nl. Nucleus. vs. g. Germinative vesicle. 



nl. gran. Nucleus of granulosa cell. z. r. Zona radiata. 



PLATE III. 



All the figures of this plate were drawn from the shell of an egg preserved in 

 cold corrosive sublimate (4 hours) followed \>y alcohol, stained in Kleinenberg's 

 hsematoxylin, sectioned in paraffine, and mounted in benzole-damar. All except 

 Fig. 3 magnified 515 diameters. 



Fig. 1. Radial section, the heads of some of the villi broken off. 



" 2. Tangential section through the heads, at A of Fig. 1. 



" 3. Similar section of four heads more highly magnified to show the deeply 

 stained peripheral portion. X 750. 



" 4. Tangential section through the middle region (B of Fig. 1) of the stalk. 



" 5. Section parallel to preceding through the region of the roots of the 

 villi (C of Fig. 1). The lower portion of the figure cuts through a 

 deeper part of the membrane (zona) than the upper portion does. The 

 middle portion shows the branching roots of the villi as they enter 

 the pore-canals. 



