DISTRIBUTION OF SPORES AND SEEDS. 365 



Hairs of the most various origin arc produced in such 

 numbers and position as to form either parachutes or tangled 

 woolly envelopes to the fruit or sec Is ( figs. 410, 41 1). 



Fig. 41" 



Fig. 409.— Heads of fruits of the dandelion; single fruits falling, exposing common 



torus and involucre. Natural size.— After Kernel . 

 Fig. 410. — Fruits of a willow, burst, and allowing the seeds, each with .1 tuft of silky 



hairs (coma), to escape. Natural size. — After Kerner. 



493. 4. Distribution by animals. — To secure this there 

 arc two general methods observable. (</) The seed or fruit 

 is cither adapted for transport by adhering to the both- of the 

 animal ; or (b) the seeds are surrounded by edible parts, and at 

 the same time so protected against the digestive juices that 

 they may pass uninjured through the alimentary canal. A few 

 plants are distributed by animals which collect and hide their 

 fruits or seeds (e.g., the squirrels 1. The adhesion of fruitsor 

 seeds to animals, especially to those which are provided with 



