24 TADACHIKA MINOURA 



male-like than those described already; but the size relations of 

 the two gonads is abnormal, the left one being larger than the 

 right. 



7. Embryo no. 45-18 (fig. 20). Operated May 1, 1919. 

 Piece of adult testis (bird six or more months old, testis 18 mm. 

 long) grafted on a seven-day-old embryo. Opened May 13th. 

 Age of embryo, 19 days; duration of graft, 12 days. 



Result : Gonads of the male type, but the left one is very much 

 larger than the right: size of left gonad, 4.3x1.2 mm.; size of 

 right one, 3 x 1.2 mm. The wolffian ducts are not very charac- 

 teristically male. A shght trace of the anterior part of the left 

 miillerian duct present; posterior part only of the right duct 

 present and attached to the cloaca as in the normal female. 



8. Embryo no. 45-6 (fig. 19). Experimental conditions the 

 same as in no. 45-18. 



Result: Gonads of the male type, but the left one larger than 

 the right, as in no. 45-6; left gonad, 4.2 x 1 mm.; right gonad, 

 3x1 mm. Wolffian ducts more or less of the female type; 

 only traces of the miillerian ducts present. 



9. Embryo no. 15-5 (fig. 18). Operated November 13, 1917. 

 Piece of adult testis grafted on an embryo ten days old. Opened 

 November 22nd. Age of embryo, 19 days; duration of graft, 

 9 days. 



Result: Left gonad of the male type, 5 x 0.9 mm.; right gonad 

 more or less of the female type, 2.7 x 1 mm. Wolffian ducts of 

 the male type. Posterior portions of the miillerian ducts present 

 on both sides, about 5 mm. in length; the left duct somewhat 

 differentiated in the female direction. 



10. Embryo no. 10-5. Operated October 3, 1917'. Piece of 

 adult- testis grafted on a nine-day-old embryo. Opened October 

 23rd. Age of embryo, 19 days; duration of graft, 10 days. 



Result: Right gonad of the male type, 3 mm. long; left gonad 

 not typically male in form, but flattened somewhat like the 

 female type gonad, 4.8 mm. long. Left gonad markedly larger 

 than the right. Wolffian ducts of the male type. Condition 

 of the miillerian ducts could not be made out, owing to poor 

 preservation. 



