2:](i 



Universih/ of CaUfornia I'uhlicaiions in Botanij \^'oh.l 



Table 7. — {Conlinuid) 



Collection 

 Number 



(13) 

 (14) 

 (15) 

 (16) 

 622 (1) ''C. 



(2) 



(3) 



(4) 



(5) 



(6) 



(7) 



(8) 



(9) 

 (10) 



(11) 

 (12) 

 (13) 



\'ai'ioty 



n. consiniilis 



Acetone 



Kxtrapt 

 l^or cent. 



2. SO 



6.12 

 13.79 

 20.33 

 4.72 

 4 . 59 

 4.20 

 5.49 

 2.15 

 2.15 

 3.42 

 2.65 

 3.29 

 4.52 

 5.52 

 10.72 

 2.12 



Benzene 



Extract 

 Per cent. 



1 



1. 

 1 

 0. 



43 

 .03 

 27 

 .01 

 . 3() 

 0.35 

 0.4S 

 0.96 

 1.56 

 2 . 36 

 2.12 

 1.88 

 1.64 

 2.39 

 0.96 

 0.83 

 0.86 



3 Collected, Ely, Nev. Feb., 1919. 



lU'riiarkrs 



Eif;fith section, 3 years old 



Shoots, 2 y(>ar,s old 



Shoots, 1 year old 



Tips, current year 



End of root, 30 cm. 



Next 10 cm. up root 



Next 10 cm. up root 



Next 10 cm. up root 



Next 10 cm. up root 



Soil line 



Main branches, 5 to years old. 



Main branches, 4 to 5 years old 



Main branches, 3 to 4 years old 



Main branches, 2 to 3 years old 



Shoots, 2 years old 



Shoots, 1 year old 



Tips, current year. 



P\)r convenience of discussion the table above ha.s been differently 

 arranjred and somewhat condensed in the table which follows: 



Table 8. — Thk Eelative Amounts of Rubber Found in Various Portions of 

 THE Root and in Portions of the Stem of Various Ages 



7o2 



.75 



1.70 

 0.42 



755 



2 . 2r) 



1.63 



0.74 



These data indicate that in Chryaoihamnui^ the root proper 

 (below a point from six to ei^ht inches below the soil line) contains 

 little or no rubber. In addition to the two species for which analyses 

 are given in tables 7 and 8 we have analyses comparing the rubber 

 content of stem and root in the case of gnaphalodea and pinifolius 

 which give rcsnlts closely similar to those above. Attention should 

 ht'iT bt' called to the fact, discussed in detail elsewhere (p. 274) that 



