HOW PLANTS BEGAN TO BE. 23 



parent and offspring, I do so, partly from cus- 

 tom, and partly to show where this reasoning leads 

 us. But in reality, in such very simple plants, 

 neither part of the divided whole can claim to be 

 either parent or child ; they are equal and similar. 

 In higher plants, however (as in higher animals), 

 we find that the main portion of the plant con- 

 tinues to live and grow, and sends off smaller por- 

 tions, known as spores or seeds, to reproduce its 

 species. Here, we may fairly speak of the larger 

 plant as the parent, and of the smaller ones which 

 it detaches from itself as its children or offspring. 



The truth is, every gradation exists in nature 

 between these two extreme cases. The different 

 types glide imperceptibly into one another. There 

 is no one point at which we can definitely say, 

 " Here reproduction by splitting or division ceases, 

 and reproduction by eggs, or by spores or seeds 

 begins." 



Again, all the earlier and simpler plants are 

 sexless; they simply grow till they divide, and 

 then the two halves continue to exist independ- 

 ently. No two distinct plants or parts of plants 

 are concerned in producing each new individual. 

 But the higher plants, like the higher animals, 

 are male and female. In such cases two distinct 

 individuals combine to form a new one. They 

 are its father and mother, so to speak, and the 

 young one is their offspring. A little grain of 

 pollen produced by the male plant unites with a 

 little ovule or seedlet produced by the female; 

 and from the union of the two springs a fresh 

 young plant, deriving its peculiarities about equal- 

 ly from each of them. How and why this great 

 change in the mode of reproduction takes place 

 is another of the questions we must discuss here- 



