THE ORIGIN OF SPECIES 177 



change to another hy means of its variabiHty. Besides, the 

 illusion of variability is not created by the presence of these small 

 species alone. As Bateson says : " When this variability is 

 sorted out, and is seen to be in part a result of hybridization, in 

 part a consequence of the persistence of hybrids by partheno- 

 genetic reproduction, a polymorphism due to the continued 

 presence of individuals representing various combinations of 

 Mendelian allelomorphs, partly also the transient eifect of altera- 

 tion in external circumstances, we see how cautious we must be 

 in drawing inferences as to the indefiniteness of specific limits 

 from a bare knowledge that intermediates exist." The author 

 expressed his firm conviction, as explained before, that no trans- 

 mittable variation exists, and that all apparent variability is due 

 to an original cross. 



Finally, the author proceeded to the origin of species before 

 sexual reproduction took place. He laid stress on the fact that 

 this of course is mere speculation. 



As such he offered the following points : — 



(1) If a species is a perfectly stable genotype, reproducing 

 faithfully its kind for ever, unless crossing interferes, all 

 differences between the individuals belonging to a geno- 

 type must be non- inheritable modifications. 



(2) Inheritable variability does not exist, with the always 

 possible exception of mutation through loss of factors. 

 All that has been described as variability is the result of 

 vegetative or generative segregation of heterozygotes. 



(3) No inheritance of acquired characters occurs. The total 

 of the inheritable factors now found among higher 

 organisms must have been present in the total of the 

 " urorganisms," each of which, however, possessed but a 

 small number. 



[At the meeting of the same Society on June 4, the Eev. George 

 Henslow gave an address on "Darwin's Alternative Explanation of 

 the Origin of Species, without the Means of Natural Selection," 

 of which the following abstract was supplied.] 



The cause of variation, always " changed conditions of Life," 

 with " Definite or Indefinite Results " {Variation, £c. vol. ii. p. 272, 

 1868). 



Natural Selection is not a cause : e. g. Mivart {Origin, dx. 

 6th ed. ch, vii.). Also, E. W. Hutton, who says : — " Having 

 Natural Selection to be a true cause, and one that largely explained 

 the Origin of Species from Varieties, by causing a gradual diver- 

 gence of character, &c." {Darioinism and Lamarckism, p. 38, 1899). 



No necessity for the words " several generations " for giving 

 rise to a variation, as plants vary at once ; but they are required 

 for fixing them so as to be heredity under any conditions. 

 "Species" and "Variety" are terms representing the varying 

 amounts of change necessary for adaptation. Hence there need 

 be no intermediate forms. 



First reference to " definite action," &c., as a cause {Origin, &c. 



Journal op Botany. — Vol. 52. [July, 1914.] r 



