556 



150TANY 



PART ri 



with one pendulous anatropous ovule. Widely distributed 



uniloculai-j 

 family. 



Important Representatives. — In addition to the Mulberry trees, of wliich 

 Morns alba is cultivated for the rearing of Silk-worms and M. nigra (Fig. 491, B) 

 as a fruit-tree, the genus Ficus deserves special mention. The species occurring 

 farthest north is the Common Fig {Ficus carica, Fig. 532), which is endemic to 

 the Mediterranean region, and has l)een long cultivated. It is a low tree with 

 palmately incised leaves and stipules, which form a cap-like protection to the bud. 

 The inflorescences are hollow, pitcher-shaped structures with a narrow opening. 

 The flowers are borne closely crowded together ou the inner surface. The flat, 

 disc-shaped inflorescences of Dorstenia wliich bear the flowers on the upper surface 

 are in many respects corresponding structures (-^). The pollination of the Fig is 



eff'ected by a species of wasp, 

 which lays its eggs in the short- 

 styled female flowers or gall- 

 flowers. The sweet, fleshy portion 

 of the edible Fig is developed 

 from the hollowed axis of the 

 inflorescence together with the 

 perigones of the individual flowers. 

 The small, hard, seed-like bodies 

 are the fruits developed from the 

 ovaries of the small flowers. Some 

 species of Ficus are among the 

 largest trees of tropical forests. 

 The most remarkable is the Banyan 

 {Ficus henrjalensis), which occurs 

 in the East Indies. The seeds, 

 carried by fruit-eating birds, ger- 

 minate on the branches of trees, 

 where the plant develops as an 

 epiphyte. The proper form of 

 the tree is only seen, however, 

 after the roots have reached the 

 soil, and it is no longer dependent on the scanty food supply obtainable in the 

 epiphytic position. The host-plant is gradually strangled, additional roots are 

 sent down to the soil and thicken into pillar-like supports, ami ultimately a 

 small wood capable of sheltering an entire village is developed from the single 

 small seedling. The latex of Ficus clastica is obtained from the tree by making 

 incisions in the bark, and serves as one source of india-rubber. Castilloa clastica 

 is another important rubber-tree of Central America. The gigantic inflorescences 

 of species of Artocarfus when in fruit are eaten raw or cooked and form the Bread- 

 fruit of the Tropics. 



The sjjecies of Cccroina are American myrmecophilous trees ('-"). The ant-plant 

 theory propounded and established by Fritz Muller and Schimper is based 

 largely on Cccroina adcno2nis, a common tree of tropical America. This harbours a 

 species of ant in the hollow internodes of the stem and also bears albuminous 

 "Muller's bodies " on the leaf-bases; these are utilised as food by the ants. 

 According to the hypotliesis advanced tliese provisions of house-room and food to 

 a war-like species of ant are adaptations to enable the jtlant to withstand the attacks 

 of leaf-cutting ants. The latter cut out pieces from tlie leaves and carry them to 



Fio. 532. — Ficus carica. A, Longitudinal section of 

 an inflorescence. B, Fertile flower. C, Gall-flower. 

 D, Male flower. {B-D, enlarged ; D, after Keener ; 

 B, C, after Solms-Laubach.) 



