TABLE OF CONTENTS. 
Page. 
Preface - - ill 
Letter to C. R, Markham, Esq,, C.B. - - - - - vii 
' *’ $ W .... V- r. 
Introduction. — General geographic distribution (with map, &c.) - - ix 
Part I. — Natural Order Euphorbiacea: : 
1 . American sources of supply — 
Hevccc species, geographic distribution, &c., and climatic 
conditions - ------ 1 
Collection and preparation of the caoutchouc - 8 
Commercial varieties - - - - 9 
Natural Order Autocar pace a; : 
1. American sources of supply — 
Castilloce species, geographic distribution, climatic conditions 1 1 
Collection and preparation - - - 15 
Commercial varieties - - - -16 
2. Asiatic sources of supply — 
Ficus clastica , geographical distribution, climatic conditions 
(with map) - - - - - -18 
Collection and preparation - - - - 20 
Commercial varieties - - - - - 21 
Natural Order Apocynaceai : 
1. American sources of supply — 
JIancornia speciosa, etc., geographic distribution, &c. - 23 
2- Asiatic sources of supply — 
Urceola clastica, geographic distribution, &c. - - 24 
3. Asiatic and African sources of supply — 
Willughbeia edulis, geographic distribution, &c. - - 25 
4. African sources of supply — 
Madagascar. Vahece species, &c., geographic distribution, # 
&c. 26 
West coast, &c. Landolphicc species, geographic distri- 
bution, &c. - - - - - 27 
