3l8 THE DOCTRINE OF DESCENT. 



tion is necessarily limited by the means of subsistence, and that 

 the growth increases in proportion to the means of subsistence, 

 setting aside some special impediments easily discovered. These 

 , impediments, which always keep the population below the amount 

 warranted by the means of subsistence, are moral restraint, crime, 

 and misfortune. Malthus depicts the struggle for existence without 

 pronouncing the word ; he demonstrates that the dreams of a 

 future blissful equality of all mankind on the^ earth transformed 

 into a vast garden, are based upon delusions. Each individual 

 must much rather labour indefatigably to ameliorate his position. 

 By the experience of breeders and gardeners he knows that 

 animals and plants may be improved and ennobled. No organic 

 ennoblement of the human race as a whole is perceptible, nor can 

 the human race be ennobled save by condemning the less perfect 

 individuals to celibacy. 



These, and similar thoughts in the work of Malthus, first sug- 

 gested Darwin's theory, as he has informed us. 



*' Variation of Animals and Plants. I. loo. 



" Two treatises by A. Kemer are also very instructive with 

 regard to the question of species: "Gute and Schlechte Arten.'' 

 (Innsbruck, 1866.) And " Die Abhangigkeit der Pfianzenwelt von 

 Klima und Boden. Ein Beitrag zur Lehre von der Enstehung und 

 Verbreitung der Arten, gestiitzt auf die Verwandtschaftsverhaltnis>;e, 

 geographische Verbreitung und Geschichte der Cytisusarten aus 

 dem Stamme Tubocytisus D.C." 1869. Kemer 's latest work, "Die 

 Schutzmittel des Pollens" (Innsbruck, 1873), is likewise an ad- 

 mirable investigation of the variability, adaptation, and formation 

 of species. 



" Origin of Species. 13th ed. p. 84. 



" Origin of Species. 13th ed. p. 96. 



*° Origin of Species. 



*' P. 7. The following pages contain an epitome of the objec- 

 tions offered to the inadequacy of the theory of selection. 



" Moritz Wagner, Die Darwin'sche Theorie und das Mig^ations- 

 gesetz der Organismen, 1848. 



'" Nageli, Enstehung und Begriff der naturhistorischen Art. 

 (Sitzungsberichte der bairischen Akademie der Wissenschaften), 



