216 ON THE REPRODUCTIVE HISTORY OF THE MOLE. 
Puate II. 
Fig.3. Section of pelvis of 27 mm. embryo at a higher level than figs. 1 & 2 (Pl. I.). 
Section passes through the base of the genital tubercle and cuts through 
the urethra in three places. 
3a. Key to show the planes of sections illustrated in figs. 1-3. 
4, Section of pelvis of 33 mm. embryo showing the double Mullerian ducts. 
Puate III. 
Fig.5. Section of pelvis of 33 mm. embryo at a slightly lower level than fig. 4 
(Pl. II.). The section passes below the caudal bend of the urethra and 
shows the lower ends of the Mullerian ducts, the strand of tissue in which 
they terminate, and the epithelial ingrowths from the base of the genital 
tubercle. 
6. Section of pelvis of 59 mm. nestling, just shaving the base of the genital 
tubercle. In more caudal sections the lumen A becomes continuous with 
the lumen B. 
