234 PLANT LIFE 



complex, so clearly related to the sexual act, 

 and so similar in its details in the animal and 

 vegetable kingdoms alike, can be devoid of sig- 

 nificance. It emphasises the individuality of 

 the chromosomes in the strongest way, and in 

 this respect it is in accordance with results of 

 many experiments which indicate that the 

 chromosomes are, as a matter of fact, different 

 from one another, i. e. possess an individuality 

 of their own. Moreover, we see that in the 

 nuclei before meiosis, the chromosomes are 

 present as pairs of homologous individuals, 

 the individuals of each pair having originated, 

 one from the sperm, the other from the egg, 

 at the act of fertilisation to which the plant 

 owed its existence. Furthermore, there is 

 a considerable body of evidence to show that 

 the chromosomes in some way represent the 

 agents by which hereditary qualities are trans- 

 mitted from each parent. Meiosis provides 

 an obvious method by which the qualities, 

 through the agents that are responsible for 

 them, may be shuffled in the sexual cells; 

 and, as a matter of fact, when hybrids are 

 inbred, or when plants are crossed with one 

 another in a variety of ways, we find the 

 results agree in practice very closely with 

 what is deduced as possible from a study of 

 the behaviour of chromosomes. Indeed, it is 

 not going too far to say that in meiosis and 

 fertilisation we are witnessing the chief act 

 of distributing and recombining the very 

 substances which determine the possibilities 



