38 PLANT LIFE. 



food material is packed inside the leaves of the embryo 

 itself It is very exceptional to find several embryos in 

 one seed ; in this case the struggle for existence begins 

 before the seed germinates, and the strongest embryo 

 generally destroys all the others. 



There are therefore besides the embryo five distinct 

 parts in the orange fruit ; each for a different purpose. 



1. The Peel, with oily matter which protects the 

 sugar. 



2. The Colour to attract the animal. 



3. The inducement for the animal to eat it ; in this 

 case Sugar and Fruit Jelly. 



4. The tough Seed-coat which protects the seedling. 



5. The Food store of the seedling. 



6. The Embryo or germ itself (4, 5 and 6 are dis- 

 cussed in Chapters 3-5). 



(i) Protection of the sugary material is generally 

 secured by a modification, or extra development, of 

 some of the different weapons which plants employ 

 against weather, or against animal attacks. The orange 

 is closely allied to the Rue family, which is generally 

 aromatic, and it has improved and specialised this family 

 characteristic of producing essential oils. The bloom 

 of the Grape is due to a thin, waxy coat which un- 

 fortunately is insufficient to always protect the berries 

 from fungi. The Peach and the Gooseberry have long 

 hairs, and a distinct skin, much tougher in the wild 

 plant than in the cultivated varieties. The apple has a 

 thin layer of corky matter. The Pomegranate, on the 

 other hand, has a thick woody shell, and only a creature 

 with strong teeth is likely to reach the seed. A very 

 peculiar form of protection is that adopted by the 

 Prickly Pear, a cactus common in India. Here the 

 tissue which surrounds the fleshy part is full of minute 



