tnmEAK socTETV or loxdox. xxxvu 



an abstract form. In treating of a genus, a species, or a variety, it 

 is not enough to have one individual before our eyes ; we must com- 

 bine the properties belonging to the whole race we are considering, 

 abstracted from those peculiar to subordinate races or individuals. 

 We cannot form a correct idea of a species from a single individual, 

 nor of a genus from a single one of its species. We can no more 

 set up a typical species than a typical individual. If we had before 

 us an exact individual representative of the common parent from 

 which all the individuals of a species or all the species of a genus 

 have descended — or, if you prefer it, an exact copy of the model or 

 type after which the whole species or genus had been created — we 

 should have no possible means of recognizing it. I once heard a 

 lecture by a German philosophical naturalist of considerable reputa- 

 tion in his day, in which he thought he proved that the common 

 Clover was the type of Papilionaceae. His facts were correct enough, 

 but his arguments might have been turned in favour of any other 

 individual species that might have been selected. Suppose two 

 individuals of a species, two species of a genus, two genera of a 

 familj', in one of which certain organs are more developed, more 

 differentiated, or more consolidated than in the other ; if we agree 

 upon the question of which is the most perfect, a point upon which 

 naturaKsts seldom do agree, how are we to determine which repre- 

 sents the common parent or model ? whether the perfect one is an 

 improvement upon or an improved copy, or the imperfect one a de- 

 generacy from or a bad imitation of the other ? l^o direct evidence 

 goes beyond a very few generations ; reasoning from analogy is 

 impossible without dii'ect evidence to start from ; and the imaginaiy 

 type without cither is the business of the poet, not of the naturalist. 



It follows that every such abstract idea of a race must be derived 

 from the observation, by ourselves or by others, of as large a number 

 of the constituent individuals as possible. However fixed a race 

 may be, if fixed at all, in nature, that is not the case with our 

 abstract idea of it : no species or genus we establish can be consi- 

 dered as absolute ; it will ever have to be completed, corrected, 

 or modified, as more and more individuals come to be correctly 

 observed. Hence it is that a species described from a single speci- 

 men, and even a genus established on a single species, always 

 excites more or less of suspicion, imless supported by strong reasoning 

 from analogy or confinned by repeated observation. 



Our means of observing and methodizing biological facts, of 

 establishing and classif)ing those abstract ideas we caU varieties, 

 species, genera, families, &c., consist in the study (1) of living 



jjOnx. PKoc. — Session 1870-71. / 



