SHREVE PLATE 1 
A. Parkinsonia microphylla, end branch of a tree. 
B. Plants of Parkinsonia used in experiments VI-X. Counting from left to right, Nos. 1-3 were raised 
in the green-house, Nos. 4-5 were grown under natural conditions having been transplanted to pots 
a short time before the experiments. Nos. 1-4 are one year old. No. 5 is about eight years old. 
C. Parkinsonia microphylla, adult tree. 
