1 94 APPENDIX 



appearing in all directions. It would be sure to follow that after a time there 

 might be some congenital variation that affected the shape of the hands and 

 feet. These would not be produced as the result of the use of the organs or 

 as acquired variations, but simply from variations in the germ plasm. There 

 might be thousands of other variations in other parts of the body in the mean- 

 time. The miscellaneous variations, however, would not persist. But as 

 soon as variations appeared which affected the shape of the hands and feet, 

 the fact that the animal had continued to climb trees would make these varia- 

 tions of value, and therefore subject to natural selection. Selection would 

 follow, and thus in time the monkeys might be expected to inherit hands and 

 feet well adapted for climbing. The acquired variations, in such a case, 

 had nothing to do with producing the changes directly, but they did shield 

 the animal from destruction until congenital variations appeared. Acquired 

 variations have determined that the individuals shall live in trees, and this 

 life has determined what congenital variations will be preserved. Indirectly, 

 therefore, acquired variations guide evolution." 



On page 28 I wrote: "In a species which withstands unfavorable environ- 

 mental conditions through the plasticity of its individual members, each 

 individual will need to be educated into harmony with the environment. 

 Such individuals of the species as vary toward greater natural adaptation will 

 need less education. Of course innate adaptation is more advantageous than 

 adaptation through education, since it is immediate, no period of disadvan- 

 tage appearing in the early life of the individual. The death-rate of the in- 

 dividuals which become adapted through education may be greater than that 

 among the individuals with more perfect innate adaptation. Thus, in time, 

 innate adaptation may be established for the species as a whole." 



When the innate adaptation is by means of a character similar to that ac- 

 quired by the plastic individuals through education, the only advantage which 

 the innately adapted will have will be from the fact that they pass through 

 no stage in their youth when, being as yet insufficiently modified, they are not 

 well adapted to their environment. This is a real advantage and, in a species 

 whose individuals become modified slowly or imperfectly, the advantage 

 to the innately adapted may be of selection value. But if the ontogenetic 

 adaptations are prompt and sufficient, the innately adapted individuals will 

 have but little advantage. That is, when plasticity is very marked, it will 



