DISPERSAL BY BIRDS 



161 



275) and thistle (Fig. 27G) are examples. The silk of 

 the milkweed (Fig. 277) has a similar office, and also the 

 wool of the cat-tail (Fig. 278). Recall the cottony seeds 

 of the willow and poplar. 



303. DISPERSAL BY BIRDS.— Seeds of berries and of 

 other small fleshy fruits are carried far and wide by- 

 birds. The pulp is digested, but the seeds are not 

 injured. Note how the cherries, raspberries, blackberries, 



and Juueberries spring up in the fence- 

 rows, where the birds rest. Some ber- 

 ries and drupes persist far into winter, when they sup- 

 ply food to cedar birds, robins, and the winter birds. Fig. 

 279. Red cedar is distributed by birds. Many of these 

 pulpy fruits are agreeable as human food, and some of 

 them have been greatly enlarged or "improved" by the 

 arts of the cultivator. Consult paragraph 379 for the 

 process by which such result may have been attained 



304. BURS.— Many seeds and fruits bear spines, hooks, 

 and hairs which adhere tc the coats of animals and to 



