72 NATURE STUDIES. 



egg into a living chicken. But, as soon as the young 

 plant has used up all the material laid by for it by its 

 mother, it is compelled to feed itself just as much as 

 the chicken when it emerges from the shell. The 

 plant does this by unfolding its leaves to the sun- 

 light, and so begins to assimilate fresh compounds of 

 hydrogen and carbon on its own account. 



Now it makes a great deal of difference to a sprout- 

 ing seed whether it is well or ill provided with such 

 stored-up food-stuffs. Some very small seeds have 

 hardly any provision to go on upon ; and the seedlings 

 of these, of course, must wither up and die if they do 

 not catch the sunlight as soon as they have first un- 

 folded their tiny leaflets ; but other wiser plants have 

 learnt by experience to lay by plenty of starches, oils, 

 or other useful materials in their seeds ; and where- 

 ever such a tendency has once faintly appeared, it has 

 given such an advantage to the species where it 

 occurred, that it has been increased and developed 

 from generation to generation through natural selec- 

 tion. Now what such plants do for their offspring, 

 the hyacinth, and many others like it, do for them- 

 selves. The lily family, at least in the temperate 

 regions, seldom grow into a tree-like form; but 

 many of them have acquired a habit which enables 

 them to live on almost as well as trees from season to 

 season, though their leaves die down completely with 

 each recurring winter. If you cut open a hyacinth 

 bulb, or, what is simpler to experiment upon, an 

 onion, you will find that it consists of several short 



