what we today call Hevea brasiliensis, he did not enter 
into a discussion of the reason why it was so according 
to the Rules and why the name cannot, under any cir- 
cumstances, be applied to the Orinoco material. In spite 
of the fact that Chevalier’s paper constitutes the most 
important contribution of the century towards a clarifica- 
tion of this question, it has apparently not received the 
attention it deserves. Baldwin (in Journ. Hered. 38 
(1947) 54; ibid. 40 (1949) 47) accepted Chevalier’s con- 
clusions, but other investigators who have recently pub- 
lished on Hevea (Schultes in Bot. Mus. Leafl. Harvard 
Univ. 12 (1945) 7; Seibert in Ann. Missouri Bot. Gard. 
34 (1947) 305), by using ‘‘(HBK.) Muell.-Arg.’’ as 
authorities for the binomial Hevea brasiliensis, have in- 
dicated acceptance of the long-established belief that 
Kunth’s publication of Stphonia brasiliensis was the 
earliest. 
Cook, in 1941, went much farther than all who had 
previously discussed this problem. He _ proposed (in 
Journ. Wash. Acad. Sci. 31 (1941) 46) to substitute the 
new name Siphonia Ridleyana Cook for our cultivated 
rubber tree. He rejected the generic epithet Hevea on 
the basis of faulty reasoning and an erroneous under- 
standing of the meaning of the term homonym. Even 
were a new name needed, Cook’s substitute specific epi- 
thet would be superfluous in view of Warburg’s Hevea 
Siebert of 1900. Cook did not mention Warburg’s work 
in his rather extensive discussion, nor did he indicate by 
citation or by context that he was familiar with Cheva- 
lier’s convincing article. 
To help end the continued uncertainty in regard to 
the name of such an important economic plant, and to 
reiterate Chevalier’s conclusion and connect the reasons 
for it with the corresponding authorizing Article of the 
International Rules of Botanical Nomenclature, I shall 
[ 81 ] 
