46 MICHAEL F. GUYER 



various other gallinaceous birds, such as peafowls, pheasants, 

 guineas, and bantam chickens. As long as both were alive they 

 remained together constantly but . after the one was killed the 

 other attached itself to the guinea contingent of the enclosure. 

 Whether this was due to an instinct of kinship or whether it was 

 the result of earlier associations with the guinea mother I am 

 unable to say. 



Upon opening the body cavity the testes in three of the hybrids 

 were found to be normal in size and external appearance. In 

 the fourth, while the left testis was somewhat smaller than the 

 average, the right was greatly hypertrophied, weighing 90 grams 

 and measuring 85 mm. long by 54 mm. broad, by 30 mm. thick. 

 The enlarged testis was kidney-shaped and lay diagonally across 

 the body cavity. Two distinct regions, separated externally 

 by a shallow furrow and internally by more or less of a connective 

 tissue septum, were visible. The anterior region, representing 

 about one-third of the testis, was a white, waxy, fatty mass. The 

 remaining portion was somewhat more firm and was richly 

 supplied with small blood vessels which at intervals exhibited 

 numerous plexuses and varicosities. 



Toward the anterior end of this hypertrophied organ and marked 

 off from it as a distinct body by a constricted band of connective 

 tissue was what appeared to be a srriall accessory testis. Subse- 

 quent microscopic examination showed that the left testis, the 

 posterior region of the hypertrophied right, and this smaller 

 accessory body all contained seminiferous tubules, although 

 they were comparatively scarce in the hypertrophied body. Such 

 a hypertrophied condition of one testis has been noted by other 

 students of hybrids such as Suchetet,^ for instance, who in speak- 

 ing of a hybrid duck (C. moschata X A. boschas) states that one 

 of the two testes had the dimensions greatly exaggerated, and 

 with its juices devoid of spermatozoa. Although, with the 

 exception just mentioned, the testes of the hybrids appeared 

 normal from a macroscopic examination, microscopic investiga- 

 tion showed them to be markedly abnormal; to such a degree in 

 fact that no trace of spermatozoa were observable although in 



' Suchetet, Andr6: Des hybrides a I'etat sauvage; Oiseaux, Tome 1, 1896. Lille. 



