416 LOTSY, CURRENT THEORIES OF EVOLUTION. 
argentatum grows, were flooded and others remained above water, 
we would obtain on such islands a similar distribution of closely 
related Parthenium-species, as we now find in the case of animals 
and plants on the Galapagos-islands, and I think the Parthentum- 
case a particularly good one, because Dr. MACALLUM could show 
that its forms possess a considerable amount of shrivelled pollen 
which is, to say the least, a suggestive indication of their hybrid origin. 
So it seems to me, that, at the present moment, the most pro- 
bable view of evolution, is evolution by means of hybridization 
and this view seems to me so very natural, not only because it 
is based on that very general property of living matter: sexual 
reproduction and explains its meaning but also because it brings 
the origin of diversity in lifeless nature — chemical combination — 
into line with that in living nature: hybridization. 
I might: stop here, were it not that I have heard it objected 
that on the basis of my views, which do not admit the existence 
of mutation, | must assume that the urplasmata contained already 
all those bearers of the millions of characters now exhibited by | 
living organisms. 
This objection of course is again based on the assumption of 
‘the existence of organoid gens, an assumption which I consider 
to be ill-founded. 
I certainly do not accept the presence of all present day so 
called gens in the urplasmata, but if we do not speak of gens — 
hypothetical things — but of potentialities, | do not see any objection 
against the assumption that all what has been realised was already 
present zn. potentia in the urplasmata, because this must evidently 
have been the case, as otherwise it never could have been realised. 
Ex nullo nihil fit. 
If in the atoms the potentiae to form chemical combinations 
had not been present, these chemical combinations could never 
have been formed. 
xs 


