SEED CARRYING DONE BY ANIMALS 



445 



used as food by the plant itself or, in general, by its seeds. 

 There are, therefore, several points to be explained on the basis 

 of possible advantages to the plant. These are: 



1. The eatable nature of the pulp of many fruits. 



2. The bitter or other unpleasant taste of many seeds, as 

 those of the orange and lemon. 



3. The hardness or toughness of many seeds of pulpy fruits, 

 as the date and the peach. 



4. The small size and indigestibility of seeds of pulpy fruits, 

 as the fig and the raspberry. 



A little observation in the field suffices to show that most 

 pulpy fruits are habitually eaten by birds or other animals large 

 enough to carry them away from the parent plant. Seeds of 

 disagreeable flavor, and very large 

 hard seeds are often avoided by the 

 animal in eating the fruit which 

 contains them. Small hard seeds 

 are commonly swallowed whole and 

 frequently remain nearly unacted 

 upon by the digestive fluids, so that 

 they traverse the digestive tract of 

 the fruit-eating animal which swal- 

 lowed them and remain perfectly 

 capable of germination. In this way 

 such instances of dissemination as 

 those of the raspberry (Fig. 346) and 

 the red cedars (Fig. 347) are readily 

 explained. 



421. Seed carrying purposely 

 done by animals. In the cases re- 

 ferred to in the preceding sections, animals have been seen to 

 act as unconscious or even unwilling seed carriers. Sometimes, 

 however, they carry off seeds with the plan of storing them for 

 food. Ants drag away with them to their nests certain seeds 

 which have fleshy growths on their outer surfaces. Afterwards 



C FIG. 346. Red rasp- 

 berry bush, in fork 

 of a maple 



