6 BULLETIN 1057, U. S. DEPARTMENT OF AGRICULTURE. 
Bories was the first to introduce the drug into France. On page 4 
of the above-mentioned paper he says, regarding the seeds : " Their 
albumen is plentiful, oily, and holds a pair of flat foliaceous heart- 
shaped cotyledons with a bulky radicle." This shows at once that 
Bories undoubtedly had Taraktogenos kurzii seeds, as those of Gyno- 
cardia odorata have no foliaceous cordate cotyledons and have a lat- 
eral instead of a basal radicle. 
In the year following (1899) Desprez made the discovery that the 
seeds used were not those of Gynocardia odorata. 
To George Watt, the reporter on economic products of India, much 
credit is due for solving the mystery regarding the true source of 
chaulmoogra oil. Watt had plants collected, through the conservator 
of forests of the Chittagong division, of what purported to be the 
source of chaulmoogra oil. They were collected in the Kassalong 
forests in the Chittagong Hill tracts. Watt sent the specimens to 
Col. Prain, who, in a letter to Watt, dated June 28, 1900, wrote 
as follows : 
Your 14421 from Chittagong is a great find. These are the real chaulmoogra 
seeds of the Calcutta bazaar and of the Paris and London drug dealers. It is 
certainly not a Gynocardia. I believe it is a Hydnocarpus and so now do my 
friends in Paris. . . . 
Col. Prain finally identified it with a plant collected by S. Kurz in 
Pegu, Burma, which Kurz had- erroneously regarded as Hydnocar- 
pus heterophylla Bl. (a species occurring in Java), but which Sir 
George King, who worked up the species of Hydnocarpus and Tarak- 
togenos, had described in 1890 as a species of Taraktogenos and had 
named T . kurzii in honor of the collector. The source of the true 
chaulmoogra oil was thus established. 
A number of species known as kalaw occur in Burma, however, 
especially in Lower Burma ; and the seeds of these species, which re- 
semble those of Taraktogenos kurzii, are also sold on the market and 
in the bazaars. One of these so-called kalaw trees the writer had an 
opportunity to identify as Hydnocarpus castanea Hook. f. and 
Thorns. ; it occurred in the Martaban Hills of Lower Burma. It is 
quite probable, then, that not only Taraktogenos kurzii but, to a less 
extent, closely allied plants, such as Hydnocarpus castanea and other 
species of Hydnocarpus and Taraktogenos as yet undescribed, are 
sources of the chaulmoogra oil of commerce. No absolute statement 
of the source of commercial chaulmoogra oil can therefore be made so 
long as the seeds are gathered from wild-growing trees in different 
parts of Burma, Lower Bengal, and Assam. Only when Taraktogenos 
kurzii is grown as a plantation crop for the production of the oil can 
a definite statement be made with regard to the source and purity of 
the latter. 
