220 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I40 



The answer to the first part of the first question (p. 205) is, then, 

 "No, the branches within a single tree do not necessarily correspond 

 with each other." To what extent there is a correspondence may be 

 observed from the sixth column in table 157. 



Question (2) on page 205 reads: "Does the amount of correspond- 

 ence vary from tree to tree under the same general environment?" 

 This question can be investigated intraspecifically and interspecifically. 

 If one groups the various species (as from table 157), he sees at once 

 that the range of agreement is narrowed considerably. Examples of 



Table 158. — Average agreement among the branches of trees in different species. 

 Derived from table IS7 



Number 

 of 

 Species trees 



Con P I 



Con T 2 



MP I 



SA 2 



TTAp 2 



TTC 9 



TTCw I 



TTJ 2 



TTL 2 



TTM 2 



TTP 5 



WAp I 



WCh, WPe, WPl.. 4 



XSC 10 



XSJf 2 



XSP 2 



the range of agreement are: Arizona cypresses, TTC, 44 to 100 per- 

 cent ; junipers, TTJ, 38 to 60 ; honeylocusts, TTL, 60 to 100 ; apple, 

 TTAp, no variation ; maples, TTM, zero to 36 ; pines, TTP, 4 to 52 ; 

 Arizona cypresses, XSC, 46 to 100; and pines, XSP, 12 to 34. 



In spite of this lessened range, trees of the same species in the same 

 general habitat do vary among themselves in the amount of agreement 

 among their branches. 



Table 158, which is derived from table 157, sets forth the average 

 agreement among the branches of the trees in different species (col- 

 umn 6). A percentage of o to 30 may be classified as low average 

 agreement, 31 to 70 as medium, and 71 to 100 as high. Thus, the 

 gymnosperms may be grouped in order, low: Con P, Con T, TTP, 

 and XSP; medium: TTJ, XSJf, and TTC; high: XSC and MP. 



