

LOTSY, CURRENT THEORIES OF EVOLUTION. 411 
has existed from the moment that life arose, and here we come to 
the point where the limit of the influence of hybridization is reached. 
All we know of hybridization is connected with the nucleus, 
with the chromosomes; the cytoplasm is out off its reach. 
While I am writing this, I am looking upon the majestic masses 
of granite in the Yosemite-valley; they have been modified by 
erosion, by freezing and thawing, by the scorching of the sun and 
by glacial action, and the marvellous scene upon which I am looking 
is the result of all these modifying agents. But that imposing scene 
was, in the last instance, determined by the structural properties 
of the granite itself; had the rock been of another kind, then the 
result would have been another too. 
An analogon to the granite in lifeless nature, is, it seems to me, 
the cytoplasm in the living world; it is, I take it, the cytoplasm 
which determines the nature of the great phyla, it are the chromo- 
somal sets, whose composition changes continuously by repeated 
hybridization, which have differentiated within these phyla the 
smaller groups up to the so called species. 
Similar views, though not going to the extent here accepted, 
have been expressed by CONKLIN and Logs so that I am in good 
company. It would of course be of the greatest importance to 
settle the size of the groups possessing the same kind of cyto- 
plasma; up tothe present moment, my efforts in this line have been 
completely frustrated, and the reason, in full accordance with the 
above surmise, is probably the very great extent of these groups. 
Such is also the opinion of palaeontologists. who are more and 
more inclined to assume that the origin of the great phyla lies 
very far back. 
In his Presidential Address at Edinburgh SCOTT states, that in 
his opinion, the idea that the Gymnosperms descend via the 
Pteridophytes from ferns, an idea which he once held himself, 
must be discarded in view of a very much older origin of the 
seedplants, probably as old as any of the accepted groups of vas- 
cular Cryptogams. In connection with this view he cites the opi- 
nion of PAUL BERTRAND, that the Cladoxyleae, a very curious group 
of plants of upper Devonian strata, have been Phanerogamia. If 
this view became confirmed, the resuit would be that the Phane- 
rogamia had come into existence as a special phylum, arisen very 
