SUMMARY OF RESULTS 229 



ment and quite special objects, habitats, or stations 

 (law of specialization and convergence), or to parasitic 

 and sessile modes of existence (law of regression). 



(4) This perfect agreement in the mode and manner 

 of the transformations and their extent, as between 

 the recent and the fossil organisms, shows that the 

 same causes which are busy to-day in alteration of 

 form were so formerly and no others, since otherwise 

 the mode and manner of the transformations could not 

 be the same in both cases. 



That, however, the extent of the changes is the same 

 now as formerly i.e. that they never completely wipe 

 out a given type shows clearly that a more thorough- 

 going transformation and alteration is excluded. That 

 which has never happened can, according to the 

 principles of natural science, also not happen. 



The organic kingdom therefore forms no unit but, 

 as established by natural research, a definite number 

 of true types, i.<e. grades of perfection. Ever more 

 and more do the investigators see that their chief task 

 consists therein, to ascertain the history of the separate 

 groups of animals and plants and to discover the laws 

 and causes of their evolution. 



How imperfectly even this limited task has so far 

 been fulfilled is shown, better than by a detailed presen- 

 tation, by the table given as an example (Fig. 48) from 

 Handlirsch l showing the pedigree of the Beetle family, 

 i.e. of a subordinate systematically classified category. 



The extended lines show actual discoveries they 



l Die fossilen Insekten, p. 1279. 



