40 THE AMERICAN NATURALIST.  [VOL. XXXIII. 
The mean temperatures, even in January and February, are 
high enough to stimulate growth zu those plants which have 
been introduced from more humid regions, but the native vegeta- 
tion remains backward, notwithstanding the warmth. The in- 
troduced fruit trees at Mesilla Park, many of them, bloom early 
and have the flowers or fruit annually destroyed by frost. Mr. 
F. Garcia has kindly given me the following illustrative data : 
Kelsey plum blooms March 5-11. Bidswell Late peach — March 5-7. 
Huanhume plum t<- Peb: 19, 20. Peento peach March 5, 6. 
Bungoune apricot “ Feb. 19, 20. Foster peach “a. : March 16-22. 
Moorpark apricot “ March 8-10. Elberta peach «March 17-22. 
The two last-mentioned peaches do not always fail. 
There is one native flower which is earlier than any of the 
above fruit trees, namely, Sophia halictorum Ckll. I have found 
this in bloom as early as January 31, and it is not injured by 
the subsequent frosts. 
This year (1898) Miss Ivah R. Mead made some studies of 
the life of the tornillo or Pluchea zone at Mesilla Park, which 
she submitted as a thesis for the degree of B.S. at the New 
Mexico Agricultural College. The following observations were 
made by her on a small selected area of the zone in question : 
March 12. Everything seemed dead, all that I could find being two tiny 
plants less than 3 cm. high. These plants were sprouts growing from 
perennial roots. 
March 29. Ten species of plants were found growing ; six were too small 
for identification; the greatest heights of any of the others were : 
Pluchea borealis... . 100M. 
Gutierrezia sarothre . 5 cm. 
ophia halictorum. . . . 9.5m. (just beginning to flower). 
Spheralcea lobata . . . . I1 Cm. 
All were perennials or biennials, except the Sophia. The cottonwood 
trees (Populus fremonti) were in bud. The mesquite (Prosopis 
glandulosa) and tornillo (P. pubescens) showed no signs of life. 
April 5. Grass getting quite green. The grass in protected places under 
the tornillo bushes is doing much better than in the open places 
April 12. Two cottonwood trees in flower. The tornillo bushes still show 
no sign of life. Sophia halictorum is ripening its seeds. 
April 23. Tornillo still dormant. Lyctum torreyi is quite green. A bush 
of Atriplex canescens in full leaf. 
_ April 25. Mesquite bushes show the first tiny green leaves, but Serie 
os still dormant. caren torreyi shows the first blossoms. 
