152 Chapters in Modern Botany CHAP. 



duced by two parent organisms, but the separated parts or 

 units are in a very deep way continuations of the life of the 

 parents, formed of the same living material as that which 

 gave origin to the parents, able therefore when separated to 

 grow into similar organisms. 



When we examine seeds, such as those of beans or peas, 

 we at once see that they are not simple structures like, 

 for instance, the eggs of birds. It is easy to convince our- 

 selves that each ripe seed already contains a young plant, 

 with a little stem and root, and in the cases above mentioned, 

 with two seed-leaves or cotyledons packed full of what we 

 know to be nutritious matter. Seeds are not comparable to 

 the eggs but to the embryos of animals. To find out what 

 corresponds to the egg we must examine under the micro- 

 scope thin slices of unripe seeds or ovules, in the midst of 

 which we may be able to see a small unit known as the 

 egg-cell. This it is which, after being fertilised by a pollen- 

 grain, develops into an embryo plant within the seed. A 

 seed is in fact the most complex and long-discarded marvel 

 within the field of botany, of which the full unravelment and 

 interpretation lies beyond the compass of the present volume. 

 In accordance with the bionomic or Darwinian principle of 

 study here advocated, the student may be advised first to 

 study its more obvious and external history of dispersal and 

 of adaptation by help of some such interesting and con- 

 venient volume as Sir John Lubbock's Flowers, Fruits, and 

 Leaves, or Kerner's Pflanzenleben, Leipzig, 2 vols., already 

 mentioned : the latter being by far the richest store of in- 

 formation accessible to the general reader, and, thanks to 

 its wealth of illustration both coloured and in the text, of 

 great use and interest even where there is no knowledge 

 of German ; after this, the minute anatomy of the seed, with 

 the comprehension of its morphological secret, and the evolu- 

 tionary meaning of this will be all the better appreciated. 



