Mar., 1912 A WEEK AF'rELD IN SOUTHERN ARIZONA 59 in the nest. The young Mourning Doves always face in the same direction. Those of the White-winged and Mexican Ground Doves always face-in opposite directions. It would be interesting to kuosv what position the young of the Inca Dove have in the nest. As I have figured it out, they should both face in the same direction like the Mourning Dove, not to keep the ratio even but because in many respects the 3, remind me very much of the latter. I have never found them nesting and consequently have no data to refer to. Leaving the forest at about four e. ?., a frail bridge over the Santa Cruz River nearly precipitated us into its muddy bottom. Mentioning this reminds me of an interesting phenomenon I have observed in connection with the above nmned river. Going in we crossed from the left bank to the rigi?t and followed a level road for several miles. While walking we found ourselves on the left bank again without having recrossed the river. It proved quite a puzzle to me until I discovered that it disappeared underground and reappeared further down in the shape of springs. On leaving the forest we stopped to look among some giant cactuses which covered a small hill. for the nest of a pair of Arizona Crested Flycatcher (Myi- Fig. 17. TYPICAL ELF OWL COUNTRY NEAR TUCSON. FLAT MESA, 'COVERED ?.VITH CREOSOTE BUSHES, AND ?.VITH SCATTERED CLUMPS OF GIANT CACTUS archus i?ic.?'icanu$ inagister). They did not seem to have a nest and as I knew it was a little early for them we did not spend much time here, but pushed on back toward Tucson. A short distauce from the village of Dos Reales I saw some Western Martins hovering around a large branching sahuaro, so we delayed our departure and went over to them. I examined all the holes carefully, but nest building had not yet begun. However, I secured a nice set of four Gilded Flicker in which incubation had started. I also found a completed nest of Arizona Crested Flycatcher but no eggs. The presence of a snake skin in the nest was of itself sufficient to distinguish this nest from that of an Ash-throat. The birds, also, were present. Continuing on to Tucson we went through the town and about eigi?t miles farther to the east. Here we cronpeal just in time to get settled before it was too dark to see. Next morning we pushed on a few miles to the Rillito, stopping to look at some giant cactus. A nice set of four Elf Owl eggs was our first reward. Incubation was far advanced, and as I climbed up my ladder the female peeked out at me and snapped her mandibles. She retreated as I got closer
