ACQUIRED ADAPTATIONS 445 



similarly responding, and if each generation wore influenced 

 ever so little by the responses of the generations before, 

 that is to say, if the acquired peculiarities were inherited 

 to any extent, the foundations laid by the pioneers would be 

 built upon by their descendants. As a result we should 

 have in successive generations the stems growing longer, 

 and the leaves more branched and finally becoming com- 

 pound. An increased sensitiveness to light might be accom- 

 panied by greater sensitiveness to contact and this might 

 lead to a coiling of the leaf-stalks around neighboring twigs, 

 thus establishing the habit of climbing by means of which 

 better exposure to light would be most economically secured 

 through utilizing for support the very bushes which had 

 made the shade. As a consequence of the starving out of 

 the upi^er ovules there would result finally a fruit the upper 

 part of which had become a mere tail-like projection sur- 

 mounting a one-sided indehiscent base. A general hairiness 

 which had been developed in all the exposed parts of the 

 plant in response to the dryness of its new environment 

 might especially affect the fruit as being now especially ex- 

 posed, and might lead even to an elongation of the tail which 

 would thereby become well adapted for enabling the wind 

 to carry the precious seed high over surrounding shrubbery. 

 In some such way as this it is conceivable that the characters 

 of a clematis may have evolved. 



The first naturalist to suggest tliat organisms had evolved 

 through the accumulation of acquired characters was Jean 

 Baptiste Lamarck, of France, who flourished in the early 

 part of the nineteenth century. His doctrine is called La- 

 marckism, or as modified by his more recent followers, Neo- 

 Lamarckism. Lamarckians have advanced much evidence 

 to show that acquired characters are often adaptive and may 

 be inherited; but while most naturalists might concede the 

 possibility of such characters being now and then adaptive, 

 the great majority of evolutionists have remained uncon- 

 vinced that acquired characters are ever fixed by inheritance. 

 So far as we know, acquired characters do not long survive 

 the conditions under which they arise. Cultivated plants 

 escaped from cultivation soon become, as we have seen, 



