THE FRUIT 155 



342. The appendages of seeds securing dissemination by 

 wind are very similar to tliose of fruits in many cases. 

 Compare, for instance, the seed of the Trumpet Creeper 

 (Fig. 276, a) with the fruit of the Elm (Fig. 265) ; and 

 the seed of the Milkweed (Fig. 276, c), possessing a coma^ 

 or tuft of hairs, with the pappus-bearing achene of the 

 Thistle (Fig. 262). 



343. Water. — The fruits of the Cocoanut Palm are 

 originally covered witli husks impermeable to sea water. 

 They sometimes fall into the ocean, and being carried 

 to distant strands are cast up by the waves and there 

 germinate. In a like manner the achenes of the Arrow- 

 head QSagittaria) — a plant which is common along the 

 margins of })onds — buoyed up by the air-filled cells of 

 the pericarp, are floated to a distance. In a number of 

 species they float for a dehnite length of time ; then, 

 when germination is about to begin, they sink to the 

 bottom. 



344. Animals. — Tlie fruits of many plants are thickly 

 set with hooks suited to catch in the fur of animals 

 (Fig. 280). The fruits are thus 



separated from the plant and car- 

 ried away, to be subsequently re- 

 moved by the animals themselves 

 or brushed off accidentall}^ Nuts 

 hidden away in the ground by squir- 

 rels must occasionally be left to 

 grow, either through oversight or 

 on occasion of the death of the de- 280. The fmit of Agri- 

 positor. Then again, edible fruits 



like the Cherry, the Apple, and the berries offer to 

 animals a substantial reward in return for the service 

 of dispersal. 



345. Ejection of the seeds is not uncommon. The most 

 familiar example is that of the Jewelweed, or Touch-me- 

 not, the ripe pods of which, when touched, burst and 

 throw the seed in all directions. The bursting is due 

 to the sudden splitting asunder and coiling up of the 



