88 ACALEniS IX GENERAL. Part I. 



SECTION V . 



INDIVIDUALITY AND SPECIFIC DIFFERENCES AMONG ACALEPIIS. 



The morphological phenomena diseussed in the preceding section naturally' lead 

 to a consideration of individuality, and of the extent and importance of specific 

 differences among the Acalephs. A few years ago the prevailing opinion among 

 naturalists was, that, Avliile genera, families, orders, classes, and any other more or 

 less comprehensive division among animals, were artificial devices of science to 

 facilitate our studies, species alone had a real existence in iiature. Whether the 

 views I have presented in the first volume of this work (p. Kio), where I showed 

 that species do not exist in anv diflerent sense from genera, fomilies, etc., etc.. 

 had any thing to do with the change which seems to have heen lirought ahout 

 upon this point among scientific men, is not for me to say. But, whatever be 

 the cause, it is certainly true, that, at the present day, the nundjer of naturalists 

 who deny the real existence of species is greatlv increased. 



Darwin, in his recent work on tlie " Origin of Species," ^ has also done much 

 to shake the belief in the real existence of species; but the views he advocates are 

 entirely at variance with those I have attempted to estaldish. For many years 

 past I have lost no oppcn'tunity to urge the idea, that while species have no 

 material existence, the}- yet exist as categories of thought, in the same way as 

 genei-a, families, orders, classes, and tiranches of the animal kingdom. Darwin's 

 lundamental idea, on the contrary, is, that species, genera, finnilies, orders, classes, 

 and any other kind of more or less coinprehensive divisions among animals, do 

 not exist at all, and are altogether artificial, differing from one another only in 

 degree, all having originated from a successive differentiaticni of a primordial 

 organic furm, imdergoing successively such changes as would at first produce a 

 A'ariety of species ; then genera, as the difference became more extensive and 

 deeper; then families, as the gap Avidened still farther ]>etween the groups; until, 

 in the end, all that diversity was produced which has existed or which now exists. 

 Far from agreeing with these views. T have, on the contrary, taken the ground 

 that all the natural divisions in the animal kingdom are primarily distinct, founded 

 upon different categories of characters, and that all exist in the sauu' Avay, that 

 is, as categories of thought embodied in individual living forms. I have attempted 



^ Dahwin (Ciiaklks), On tlic Origin of Siic- ration of favored Races in the Strnggle for Lile. 

 eios by means of Natural Selection, or the Preser- London, ISCO. 1 vol. 8\o. 



