6^5/36* 
11th May, 
7 
Dear Professor Lam, 
Your letter concerning Macaranga has been passed 
on to me by Mr.Holttum. It is mo3t kind of you to 
have investigated this matter and to give me so much 
information. Your conclusion is exceedingly interesting, 
for it seems that Macaranga triloba sensu latisslmo 
is a species that is evolving. Indeed, I am a little 
perplexed at what should be done because I wish to 
include M,triloba in an account of our common trees. 
I have just returned from a collecting trip to 
Kelantan, Pahang and Trengganu, wMre I had the 
opportunity of studying many specimens of what we call 
M. triloba and M.Hullettli , and never did I have any 
difficulty in distinguishing them even when sterile 
because leaf-shape and colour is different. I feel 
that I am right In saying that these two "species H are 
perfectly distinct in Malaya. But when collections 
are examined from other countries, as you have so 
kindly done, then the intermediates appear. I have 
t 
noticed this in other families, and that plants from 
Borneo especially often unite what appear to be distinct 
species in Malaya. We should then, I suppose, have one 
polymorphous species and so many varieties as are needed. 
In the present case, I am inclined to keep M,triloba 
and M. cornuta (* M. Hullettli ) distinct as species in 
Professor H.J.Lam, 
7 Rijksherbarium, 
Nonnensteeg 1 , 
Leiden, 
HOLLAND 
fs 
At 
