Ch. VII, 3] DISSEMINATION OF PLANTS 



363 



Fig. 262. — Fruits of 

 Cocklebur ; X 5. (From 

 Kerner.) 



chiefly by birtls, which are the most important disseminators 

 of seeds by this method. The larger fruits, Apples, Oranges, 

 Gourds, and multiple fruits, are eaten in 

 part by birds and in part by mammals. 



The pulp has very diverse morpho- 

 logical origins, as earlier noted (page 351), 

 and the protective coats to the seed are 

 either the seed coat or else a pit formed 

 from ovary wall (page 350). The claim 

 has been made that the seeds of the 

 largest fruits (those too large to be swallowed whole) mostly 

 find their protection in the slipperiness of the coats, which 

 prevents their being actually swallowed at all, though they 

 are carried some way with the fruit. 



Some seeds have bright colors without pulp, as in Abrus 

 beans, and those of the common Magnolia ; and such are 

 said to be swallowed by birds, which perhaps mistake them 

 for something edible, or else simply desire their bright 

 attractiveness, as trout take the sportsman's fly. Some 

 seeds and fruits which bear striking resemblances to insects 



are supposed by some ob- 

 servers to secure dissemi- 

 nation on that account, 

 though this is not certain. 

 R ecently it has been claimed 

 that the man}^ small seeds 

 provided with caruncles, 

 i.e. httle rounded projec- 

 tions filled with nutritive 

 food substances (Fig. 270), 

 are very effectivelj' dis- 

 seminated by ants, which 

 carry off the nutritive bodies, and incidentally the seed 

 therewith. Also snails and even fishes have been claimed 

 to carrjr seeds. 



The greatest results in the dissemination and dispersal of 



Fig. 263. — Seed pod of Martijnia lutea 

 X \. (From Le Maout and Decaisne.) 



