Characters as Adaptive and Specific. 247 



there are presumably many cases like those of Hoff- 

 mann's plants, Weismann's butterflies, &c., where the 

 hereditary qualities of germ-plasm have (on his hypo- 

 thesis) been modified by changed conditions of life, 

 we are bound to believe that, in all cases where such 

 changes do not happen to be actively deleterious, 

 they will persist. And inasmuch as characters which 

 are only of " specific " value must be the characters 

 most easily and therefore most frequently induced 

 by any slight changes in the constitution of germ- 

 plasm, while, for the same reason (namely, that of 

 their trivial nature) they are least likely to prove 

 injurious, it follows that the less we believe in the 

 functionally-produced adaptations of Lamarck, the 

 more ought we to resist the assumption that all 

 specific characters must necessarily be adaptive 

 characters. 



Upon the whole, then, and with regard to the 

 direct action of external conditions, I conclude not 

 only from general considerations, but also from special 

 facts or instances quite sufficient for the purpose 

 that these must certainly give rise to immense num- 

 bers of somatogenetic species on the one hand, and 

 probably to considerable numbers of blastogenetic 

 species on the other ; that in neither case is there any 

 reason for supposing the distinctively " specific char- 

 acters " to be other than " neutral" or <: indifferent"; 

 while there are the best of reasons for concluding the 

 contrary. So that, under this division of our subject 

 alone (B), there appears to be ample justification 

 for the statement that ' ; a large proportional number 

 of specific characters " are in reality, as they are in 



