FRUITS AND SEEDS. 261 



in this mode of dispersal are usually birds, whose gizzards 

 may crush small seeds and destroy them. 



The surface of the fruit is usually conspicuously coloured. 

 The pulp or flesh (often sweet and aromatic) may be produced 

 from almost any part of the flower: from the ovary- wall 

 (Cherry), the receptacle (Apple, Strawberry), the perianth 

 (Mulberry), etc. Sometimes the seed has a coloured fleshy 

 aril or extra seed-coat e.g. Spindle-tree, Yew, Nutmeg 

 ("Mace " aril). Most, but by no means all, fleshy and 

 bird- dispersed fruits occur on trees and shrubs (why ?). 



(3) Dry fruits (Acorns, etc.) may also be actively dispersed 

 by such animals as squirrels, etc., for these animals often forget 

 some of the hoards they lay up in autumn. This is, however, 

 an accidental mode of dispersal, and, except in the presence 

 of a hard pericarp, the structure of the fruit shows no special 

 adaptations which might render this kind of dispersal more 

 constant and profitable. 



In most cases the seeds carried by ants are provided with 

 an aril or other appendage which contains food, usually of an 

 oily nature, and which is of no direct use to the seed itself, 

 but forms an attraction for ants. Most of the plants which 

 have this interesting means of dispersal grow where ants are 

 most abundant meadow and woodland plants. Experiments 

 show that the ants take no notice of seeds which have been 

 deprived of the attractive appendage, but carry off seeds of 

 the same kind which have not been interfered with, and the 

 seeds have been observed to be thrown out of the ant-nests 

 after the appendage has been nibbled off. 



In some localities it has been found that nearly half the 

 plants growing in meadows and woods, where ants were 

 plentiful, are dispersed by the aid of these insects. A few 

 examples are Violet, Mignonette, Grorse, Fumitory, Spurges, 

 Lesser Celandine. In some cases the plant has other means 

 of scattering its seeds, but the ants help in carrying them 

 to greater distances. 



Collect, examine, and sketch fruits adapted for dispersal by adher- 

 ing to animals, e.g. Corn, Buttercup, Avens, Goosegrass, Carrot, 

 Medick, Sanicle, Hound's-tongue, Teasel, Agrimony, Enchanter's 

 Nightshade, Burdock. In examining fleshy fruits, note which parts 

 are (1) brightly coloured, (2) fleshy and edible, (3) hardened to protect 

 the seeds. 



