" SPECIES. I I 5 



to show that the whole of the phenomena of Ontogeny 

 forms a connected chain of evidence in favour of the truth 

 of the Theory of Descent and thai they can be explained 

 mly by Phylogeny. With the aid of this close causal 

 connection between Ontogeny and Phylogeny, and by 

 constantly appealing to our fundamental law of Biogeny, 

 we shall be gradually able to prove from the facts of On- 

 togeny that Man is descended from the lower animals. 



In conclusion, it must be mentioned that very recently 

 the important theoretical question as to the nature and idea 

 of "kind. :r "species, 1 ~hich is the point on which really 

 hang all the disputes about the Theory of Descent, has been 

 definitely settle! For more than a century this ques:::^ 

 3 from the most varied points of view, without 

 resulting in a satisfactory settlement During that time 

 thousands of zoologists and botanists have occupied them- 

 selves in systematically ;lis:::izuishing and describing 

 species, without, however, any clear idea of the meaning 

 of "spe:: Many hundred thousand vegetable and 



animal forms were set up and marked as good species, 

 though even those who declared them such were unable to 

 justify the proceeding, or to give logical reasons for thus 

 distinguishing them. Endless disputes arose among the 

 "pure BystematLaexs on the empty question, whether the 

 form called a species was - a good or a bad sTriirS a species 

 or a variety, a sub-species or a group," without the ques:i:n 

 being even put as to what these terms really contained and 

 comprised. If they had earnestly endeavoured to gain a 

 clear conception of the terms,, they would long ago have 

 perceived thcr. they have no absolute meaning, but are 

 ■Merely stages in the classification, or systema::; sategorieB, 

 and of relative importance only. 



