Excursion Impressions 
By FRANK STEPHENS 
The Pacific Division of the American Association for the Advance- 
ment of Science held its annual meeting in San Diego, California, 
August ninth to twelfth, 1916. Among the exeursions offered visiting 
members and their friends was one arranged by the San Diego Society 
of Natural History and the Scripps Foundation to the border of the 
Colorado Desert, a two-day trip by automobile. Its object was to afford 
visitors an opportunity to see the changes in the plant life from the sea 
coast to the arid region east of the mountains. The trip was too hurried 
for any detailed work, and as it was the height of the dry season most of 
the annual plants were ripe and dry. 
Going out the usual stage route to Imperial was followed. The 
return was over the same route as far as Campo, where we turned 
northward to Pine Valley and Descanso and to San Diego, by a route 
north of the one followed going out. The length of the round trip was 
about 220 miles. The accompanying sketch map will give the details 
of the route followed. 
The start from San Diego was made at 8 a. m., August 13th, with 
thirty-two members and their friends in six automobiles. Luneh was 
caten under the oaks near Campo. In the afternoon the party went to 
the edge of the Colorado Desert, and returned at dusk to the crest of 
the precipitous eastern slope of the mountains, where camp was made 
under the stars, as in this sparsely settled region there was not suf- 
ficient hotel accommodations for so large a party. Blankets and pro- 
visions for the party were taken along in an auto-truck. The weather 
was cool for the season, and, except a rather strong breeze during the 
night, it was very pleasant. The thermometer at camp was 76° at 
sunset and 65° at sunrise. At noon of the 14th, lunch was eaten under 
the pines in Pine Valley, and the party returned to San Diego before 
sunset. 
The principal interest of the trip was botanical. It was the wrong 
season to find many plants in flower, but quite a number of shrubs and 
perennial plants were in bloom. Butterflies and other insects were scarce. 
Few birds and mammals were seen, partly because of the disturbance 
made by the autos. Dr. Grinnell and I put out seventy-five small traps 
at the night camp and caught eighteen small rodents, of five species. 
But one geologist was with the party. 
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