CLASSIFICATION. 415 



arisen within historical times, and varieties approaching 

 to sub-species may often be produced by the horticul 

 turist in a few years. Such varieties can easily be brought 

 back to their original form, or, if placed in the original 

 circumstances, will themselves revert to that form ; but 

 according to Darwin s views all forms are capable of un 

 limited change, and, it might possibly be, unlimited re 

 version, if sufficient time and suitable circumstances be 

 granted. 



Many fruitless and erroneous attempts have been made 

 to establish some rigorous criterion of specific and generic 

 difference, so that these classes might have a definite value 

 or rank in all branches of biology. Linna?us adopted the 

 view that the species was to be defined as a distinct 

 Creation saying&quot;, Species tot numeramus, quot diverse 

 forma: 1 in principio sunt creata?, or again, Species tot sunt, 

 quot diversas formas ab initio produxit Infinitum Ens ; 

 qua} forma?, secundum generationis inditas leges, pro- 

 duxere plures, at sibi semper similes/ Of genera he also 

 says , Genus omne est naturale, in primordio tale crea- 

 tum. It was a common doctrine added to and essential 

 to that of distinct creation that these species could not 

 produce intermediate and variable forms, so that we find 

 Linnaeus in another work obliged by the ascertained exis 

 tence of hybrids to take a different view ; he says , Novas 

 species iinmo et genera ex copula diversarum specierum 

 in regno vegetabilium oriri primo intuitu paradoxum 

 videtur ; interim observations sic fieri non ita dissuadent. 

 Even supposing in the present day that we could assent 

 to the notion of a certain number of distinct creational 

 acts, this notion would not help us in the theory of classi- 



n Philosoplna. Botanica (1770), 157, p. 99. 

 Ibid, 159, p. 100. 



P AiiKEiiitates Academicaj (1744), vol. i. p. 70. Quoted in Edin 

 burgh Review, October 1868, vol. cxxviii. pp. 416. 417. 



