SPERIVIATOPHYTA— URTICALES 



405 



Ulmaceae, the elms; Moraccac, the mulberries, and Urticaceae, the nettles. The 

 Castlloa elastica of Mexico, the bread nut tree of Central America (Brosimum 

 AUcasirum) and the Cecropia of tropical America furnish rubber. 



ri^. 185. Yellow Bi^ch (Bc!jfli hi^ea). Flowering branch. 2. 

 £tamin.ite flower, enlarged. 3. Pistillate flower, enlarged. 4. Fruit- 

 ing branch. 5. Nut. enlarged. 6. Scale of fruiting catkin, enlarged. 

 7. Winter branch, showing staminate catkin. 1, 4, 7, one-half natural 

 size. (After M. M. Cheney, In Green's Forestry of Minnesota.) 



The family Moraceae contains the bread fruit (Artocarpus incisa) an im- 

 portant article of food for the natives of the Pacific Islands, and the jack 

 fruit {A. integrifoha) the fleshy envelopes of which are, however, somewhat 

 poisonous. Canoe-gum, a very good substitute for rubber, is obtained from 

 ■'his genus. The figs belong to this family also ; the sycamore fig tree (Ficus 

 Sycamorus) produces small fruit which is used in Egypt for food. The com-- 

 mon fig {Ficus Carica) is the most valuable; it includes the common and' 

 Smyrna fig of commerce, containing 60-70 per cent of grape sugar. The India 

 rubber tree {F. elastica) is the source of some of the India rubber. The ban- 



