84 PLANT LIFE. 



small beetle, and this has been supposed to keep birds 

 from touching it. Pigeons, however, are exceedingly- 

 fond of the seeds, and do not appear to object either to 

 the spines upon the fruit, the strong medicinal properties, 

 or the beetle-like appearance. In Africa, wherever there 

 are castor-oil plants in fruit, these birds are almost 

 certain to be discovered feeding upon them. Some 

 fruits again are extremely like small dead branches, as 

 for example, those of the Willow-herb and many which 

 are produced from an inferior ovary. Many of the thin 

 long pods of Cruciferae are also liable to be overlooked 

 as they are very similar to branches, especially when 

 young. 



Everyone must have noticed the spines on the Beech 

 cupule, edible Chestnut, and Horse Chestnut fruit, before 

 the latter opens. These are, of course, intended to 

 protect the fruit in its young condition, and they only 

 open to allow the nuts or seeds to escape. Similar 

 spiny protections are by no means unusual. 



The seed, which has to last through the winter, is 

 made as compact, hard, and dry as possible ; and often 

 shows a very extraordinary tenacity of life. Wheat, 

 after being dried in vacuo^ has been heated to ioo° C. 

 (2I2"F.) without its being rendered incapable of 

 germination. The seeds of vegetable-marrow, mustard, 

 barley, and pea, germinated after enduring a cold of 

 — 453° Fahrenheit (Dewar). The seeds of Oat and 

 Fennel germinated although they were exposed for 118 

 days to a temperature of — 40° F. The seed of 

 Thespesia populnea was not injured by being kept for a 

 year and a half in a dry place and in water for another 

 year. 



It has been stated that Mimosa seeds germinated 

 after a delay of 60 years ; R. Brown also found that seeds 



