xm.] CRITICISMS ON &quot; THE ORIGIN OF SPECIES.&quot; 269- 



endeavours to explain the exact order of organic nature which 

 exists ; not the mere fact that there is some order. 



And with regard to the existence of a natural system of 

 minerals; the obvious reply is that there may be a natural 

 classification of any objects of stones on a sea-beach, or of 

 works of art ; a natural classification being simply an assemblage 

 of objects in groups, so as to express their most important and 

 fundamental resemblances and differences. No doubt Mr. 

 Darwin believes that those resemblances and differences upon 

 which our natural systems or classifications of animals and plants 

 are based, are resemblances and differences which have been 

 produced genetically, but we can discover no reason for sup 

 posing that he denies the existence of natural classifications of 

 other kinds. 



And, after all, is it quite so certain that a genetic relation may 

 not underlie the classification of minerals ? The inorganic world 

 has not always been what we see it. It has certainly had its 

 metamorphoses, and, very probably, a long &amp;lt;; Entwickelungsge- 

 schichte &quot; out of a nebular blastema. Who knows how far that 

 amount of likeness among sets of minerals, in virtue of which 

 they are now grouped into families and orders, may not be the 

 expression of the common conditions to which that particular 

 patch of nebulous fog, which may have been constituted by 

 their atoms, and of which they may be, in the strictest sense, 

 the descendants, was subjected ? 



It will be obvious from what has preceded, that we do not 

 agree with Professor Kolliker in thinking the objections which 

 he brings forward so weighty as to be fatal to Darwin s view. 

 But even if the case were otherwise, we should be unable to 

 accept the &quot;Theory of Heterogeneous Generation&quot; which is 

 offered as a substitute. That theory is thus stated : 



&quot; The fundamental conception of this hypothesis is, that, under the in 

 fluence of a .general law of development, the germs of organisms produce 

 others different from themselves. This might happen (1) by the fecun 

 dated ova passing, in the course of their development, under particular 

 circumstances, into higher forms ; (2) by the primitive and later organisms 

 producing other organisms without fecundation, out of germs or eggs 

 (Parthenogenesis).&quot; 



