MAMMALS OF THE MEXICAN BOUNDARY. 109 



ground and bear red blooms as beautiful as roses. Mesquites begin 

 as shrubs no larger than the mimosa and acacia on the sandy 

 mesa, but increase to the dimensions of New England apple trees. 

 the mesquite groves of the Rillito having a decidedly orchard-like 

 appearance. On the hills across the stream the gianl cactus hold- 

 sway, giving a fascinating effectiveness to the landscape at all times 

 and a peculiar beauty when, in May, each of its huge arms unfold- a 

 coronet of white Mowers, in the midst of which white-winged doves 

 delight to settle and coo. The green-barked palo vcrde with its 

 tiny leaflets, the gold and purple flower balls attached to slender 

 branches of acacia and mimosa, and the coral-red tips of bloom 

 to the tall and wand-like stems of clustering ocotillo, give a needed 

 coloring- to these rough slopes, which require but the finishing- 

 touch of bristling bisnaga, sen-ate dasylirion, scarlet-flowered cereus 

 and choya, and yellow* nopal to complete a picture of strange beauty. 

 When I visited Fort Lowell, in April, 1885, the officers' quarters were 

 shaded and screened by a beautiful paling of living ocotillos {Fou- 

 qitivrhi .splat dens Engelmann), which bloomed, and whose leaves 

 were as freshly green as when growing naturally, although the stem- 

 were merely thrust into the ground and nailed to the porch above. 

 This thorny plant is also called candlewood and corral-wood from its 

 uses. The flowers, superficially, resemble those of the Fti.sclt.sia. 



To Col. Bernard J. D. Irwin," surgeon, U. S. Army, the science of 

 herpetology is indebted for very large collections of the reptiles and 

 batrachians of old Fort Buchanan, situated at the head of Sonoyta 

 Creek, a tributary of the Santa Cruz, near Tucson, Arizona. These 

 collections were made at the suggestion of Professor Baird, and are 

 now in the United States National Museum. Since his time other 

 species have been added to the national collection by Maj. W. H. 

 Emory, Lieuts. F. T. Bryan and J. H. Putter, of the Army: Arthur 

 Schott, Edward W. Nelson. Pierre Louis Jouy, Louis John Xantus 

 de Vesey, Henry W. Henshaw, Herbert Brown, F. X. Holzner, and 

 the writer. The list of reptiles and batrachians known from the 

 region of Tucson, Fort Buchanan, and Camp Lowell is therefore a 

 long one, as follows: 



Turtles. 



Kinosternon sonoriense Le Conte. | Terrapene sp.& 



"More important than all Colonel Irwin's contributions of notes and speci- 

 mens to the Smithsonian Institution was his early training of Charles Emil 

 Bendire, the distinguished author of Life Histories of North American Birds, 

 in exact methods of scientific observation. Bendire was then a young soldier 

 of his command, attached to the hospital corps, and stationed at old Fori 

 Buchanan and other camps in the vicinity of Fort Lowell and Tucson. 



6 The skin of a box-turtle, taken between Benson and Mountain Spring, Ari- 

 zona, May 1. 1885, and prepared by the writer, is in the collection of the Ameri- 

 can Museum of Natural History, New York. 



