THE PATH OF EVOLUTION 



then suggested the same or analogous ideas. They 

 scarcely advanced, however, beyond conjectures." * 

 The doctrines that are embodied in what is known 



as Darwinism are : 







1. The laws of Natural Selection, or the inherit- 

 ance by plants or animals of the traits of ancestors, 

 modified at times by such variations as may be of 

 advantage to the young and growing organism, and 

 which variations, if of benefit to the tribal order, may 

 be transmitted by inheritance. 



2. The law of the Survival of the Fittest, or the 

 recognition of the struggle for existence, due to the 

 constantly increasing number of plants and animals, 

 while space for them, and food in, or on the soil, is 

 limited. Those that are best fitted in strength and 

 vital forces for the struggle, or those that undergo 

 such modifications, either direct or indirect, as will 

 give them an advantage over their competitors, will 

 survive ; the less fitted and weaker ones will die out. 

 The offspring will therefore be from the strongest and 

 best of their kind. 



3. The Laws of Sexual Selection. Manifested 

 apparently, only in the higher order of plants and 

 animals, at least scarcely visible in the lowest. In 

 animals this selection is often dependent upon physi- 



* Historical Sketch prefacing the first edition of the " Origin of 

 296 



