30 president's address, 



improbable. Siucc Llio old character (length, breadth, weight) had not 

 become fixed and congenital after many thousands of successive genera- 

 tions of individuals had developed it in response to environment, but gave 

 place to a new character when new conditions operated on an individual 

 (Lamarck's first law), why should we suppose that the new character is 

 likely to become fixed after a much shorter time of responsive existence, 

 or to escape the operation of the first law 1 Clearly there is no reason 

 (so far as Lamarck's statement goes) for any such supposition, and the 

 two so-called laws of Lamarck are at variance with one another.' 



In its most condensed form my argument has been stated thus by 

 Professor Poulton : Lamarck's ' first law assumes that a past history of 

 indefinite duration is powerless to create a bias by which the present can 

 be controlled ; while the second assumes that the brief history of the 

 present can readily raise a bias to control the future.' ^ 



An important light is thrown on some facts which seem at first sight 

 to favour the Lamarckian hypothesis by the consideration that, thougli 

 an 'acquired' character is not transmitted to offspring as the consequence 

 of the action of external agencies determining the ' acquirement,' yet tlio 

 tendency to react exhibited by tlie parent is transmitted, and if the 

 tendency is exceptionally great a false suggestion of a Lamarckian in- 

 heritance can readily result. This inheritance of ' variation in tendencies 

 to react ' has a wide application, and has led me to coin the word ' educa- 

 bility ' as mentioned in the section of this address on Psychology. 



The principle of physiological selection advocated by Dr. Romanes 

 does not seem to have caused much discussion, and has been unduly 

 neglected by subsequent writers. It was ingenious, and was l)ased on 

 some interesting observations, but has failed to gain support. 



The observations of de Vries — showing that in cultivated varieties of 

 plants a new form will sometimes assert itself suddenly and attain a 

 certain period of dominance, though not having been gradually brought 

 into existence by a slow process of selection — have been considered by 

 him, and by a good many other naturalists, as indicating the way in 

 which new species arise in Nature. Tlio siii;gestion is a valuable one 

 if not very novel, but a great deal of observation will have to be made 

 before it can be admitted as really having a wide bearing upon the origin 

 of species. The same is true of those interesting observations which 

 were first made by Mendel, and have been resuscitated and extended with 

 great labour and ingenuity by recent workers, especially in this country 

 by Bateson and his pupils. If it should prove to be true that varieties 

 when crossed do not, in the course of eventual inter-breeding, produce 

 intermediate forms as hybrids, but that characters are either dominant or 

 recessive, and that breeds result having pure unmixed characters — we 

 should, in proportion as the Mendelian law is shown to apply to all 

 tissues and organs and to a majority of organism?, have liefore us a 



« iNWi/rc, vol. li., 1SP4, p. 127. 



