191 2] Wilder D. Bancroft 383 



food and drink for a sufficient length of time, he will die. That 

 is the direct result of the new conditions and does not involve any 

 adaptation. If we give a suitable man a suitable amount of a suit- 

 able alcoholic drink, he will become drunk. A more interesting 

 case is that of the action of sunlight. The direct action of light is 

 to tend to bleach out any color which absorbs the light and we find 

 that an over-intense light does tend to bleach plants,^ even though 

 these plants would have been more bleached if they had grown in 

 the dark. These illustrations are so obvious that they probably 

 seem superfluous ; but they are really obvious only when put in this 

 form. For instance, in a presidential address before the American 

 Society of Naturalists, MacDougaP discusses the question of adapt- 

 ive response to the environment and says : " Further, a critical 

 examination falls to disclose any theoretical considerations or any 

 actual facts which would connect inevitably the somatic response 

 with the nature of the excitation, outside of the specialized tropisms 

 in which specific reactions are displayed. Even in these the adjust- 

 ment is of such nature that a mechanism especially responsive to 

 contact, tendrils, for example, responds in the same manner to tem- 

 perature variations, to which the movements are in no sense accom- 

 modations or adjustments." MacDougal evidently thinks that one 

 ought to show that the change in the clinging power of the tendrils 

 with changing temperature is directly beneficial. Of course, this 

 really comes under the head of the direct action of external condi- 

 tions. It is a necessary consequence of the nature and structure of 

 the tendrils. One might just as well insist that one prove that the 

 shortening of a fishing line, when wetted, is an adaptation acquired 

 because it is beneficial to somebody or something. Mistakes like 

 this retard progress. 



Under the heading of adaptation of the organism during its life- 

 time to new conditions, we can take up this same disturbing factor 

 right over again. I do not know of any plant which develops 

 armor-plate as its way of meeting blows with an axe. It is often 

 said that the development of thorns has come about as a protection 

 against animals; but I don't imagine that anybody really believes 

 that nowadays. There is one apparently beautiful case of adapta- 



^Boehm: Jour. Chem. Soc, 34, 238 (1878). 

 * MacDougal: Science, 33, 95 (1911). 



