298 DR. H. GADOW ON EVOLUTION [Mar. 20, 



Animals and jDlants have, since the beginning of life, acquired and 

 inherited and retained whatever was better, and they have got 

 rid of imperfections, so that this whole process itself has become 

 an acquired and inherited character. Thus alone can it be 

 explained that an organism can and Avill, under new circumstances, 

 or under new and sudden stress, react in a manner surprisingly 

 quick and straight to the point. 



The Cnemidojjhori are so plastic that they still respond to 

 every new condition, and in so varied a country as Mexico they 

 are liable to meet with new conditions whenever they spread (not 

 migrate!) into regions new to them. These need not be localities 

 where no Cnemidojyhorus has been before. The whole process is 

 now very comjjlex. For instance, a clan of typical C communis 

 occidentalis may spread into locality A, which is already inhabited 

 by C. immutahilis. More likely than not, it will there assume 

 some of those characters which the prevailing conditions produce 

 or require, and the result will be a superficial resemblance to 

 G. immutahilis. Into this same locality spreads a clan of typical 

 C. mexicanits, which also assume some of the characters which 

 the aboriginal G. immutahilis possesses ; but the result in these 

 " immigrants " will not be the same, because G.'mexicanus and 

 G. comviunis are not the same. 



A great resemblance between the three kinds of lizards will 

 result in obedience to the genius loci. One of these may yield in 

 the matter of pores and arm-granules and in the pattern of colour, 

 but retaining its collar ; the other set may concede neaily every- 

 thing, but may stick obstinately to some other feature by which 

 alone it proclaims its descent. Not because that point is necessary 

 to its welfare, but because inheritance happens to be too strong, 

 at least for the present. 



The whole body, i. e. the sum total of all its characters, of 

 which we can follow only a few, is considerably influenced by new 

 environmental, bionomic conditions. All the characters, being 

 therefore in an unstable condition, or shaken up, " vary " sepa- 

 rately ; some, however, with an obvious amount of correlation : 

 with the result that many combinations are formed — some of them 

 good, others bad or indifferent, and thus, seemingly by accident. 



orthogenesis, tendency towards perfection, &c., may be referred to Hseckel's 

 discussion of these and similar subjects in his 'Generelle Morphologie der 

 Organismen,' Chap. xix. (Berlin, 1866) ; reprinted as Chap. ix. pp. 311-319 in 

 ' Pnncipien der generellen Morphologie der Organismen ' CBerlin, 1906). There, p. 312, 

 he uses the excellent term Teleosis for H. G. Bronn's "Gesetz der progressiven 

 Entwickelung." On p. 317, Naj^eli's " VervoUkommnungs-theorie," practically 

 including Eimer's Orthogenesis, is discussed. Hfeckel finds fault with Naegeli's ex- 

 pression that " all organisms have the tendency to become more complicated or perfect " 

 as leading to teleology and dualism, but Hw'ckeVs substitution of a "general mecha- 

 nical law of Nature " does not mend matters. 



The main purpose of an organism is to live ! Of course that, again, is not a 

 "purpose," but it is its business, Geschaeft, that what it is busy with, " das was er 

 schafft"! 



