'SS3-1- Brewster on a Collect io)i of Arizona Birds. 21 



Statement is thus worded on account of the doubt connected with 

 many of the descriptions. There are, however, three cases re- 

 ported as occurring in hens which are comparable. The first 

 case, tha t reported by Bechstein,* was a chicken with a testicle 

 on the right side and an ovary on the left, that is much like the 

 Pipilo. The two cases reported by Simpson f were less perfect. 

 One was simply a female bird with a half developed vas deferens 

 on the right side, the other had a vas deferens on each side. In 

 both cases there were slight mixtvu'es in the habits and plumage 

 of the two sexes. 



In the Pipilo each side was perfect after its sex and showed 

 no resemblance to the other sex, thus separating it from the second 

 example given by Simpson. The natural explanation is that the 

 two generative mounds took on the two sexes and that the acces- 

 sory structures followed the master organs. So the Wolffian duct 

 remained on one side and the Mullerian on the other. 



ON A COLLECTION OF BIRDS LATELY MADE 

 BY MR. F. STEPHENS IN ARIZONA. 



BY WII.LIAM BREWSTER. 

 {Concluded from Vol. VII. p. 2J2.) 



133. Antrostomus nuttalli(.4z^(/.) Cass. Nuttall's Whip- 

 poor-will. — Although these Whip-poor-wills were common in 

 many of the localities visited but few specimens were taken, a 

 fact largely owing to their nocturnal habits. They wei'e oftenest 

 heard in rocky places, especially among foot-hills. One killed 

 near Tombstone, on the evening of April 8, frequently alighted 

 on the ground to pick up beetles. 



123. Chordediles acutipennis texensis {Lawr.) Ridgiv. 

 Texan Nighthawk. — Represented in the collection by nine 

 specimens from the following localities : Santa Rita Mountains, 



* Naturgeschichte der Voegel, Bd. II, p. 1219. 



t Article, Hermaphroditism, Todd's Ency. of Anatomy and Pliysiology. 



