414 LOTSY, CURRENT THEORIES OF EVOLUTION. 
combinations of their parts, cause together with modifications 
the diversity which we observe within that particular syngameon 
and allow a certain amount of adaptability. This diversity however 
is limited; it does not transgress the limits of the syngameon in 
question, it is limited to such diversity as is presented by the 
different colors of eyes, of hair, or, if one prefers a morphological 
example, to the different features, or qualities of mind within for 
instance the syngameon which we call white man. 
As long as such a syngameon remains closed, as no pairing 
with members of another syngameon takes place, all characters 
considered to be characteristic of that syngameon remain constant: 
a white woman never bears a negro-child to a white man, and 
this constancy of the socalled essential characters of the syngameon 
makes taxonomists consider it as a species. ; 
When it opens, when it allows members of another syngameon 
to enter into it, much larger changes take place, evolution sets in 
as f.i. in the case when Spaniards mixed with Indians and the 
Mexicans arose, or, again, Spaniards mixed with Malays and 
Philippino’s came in existence. 
How far such changes go, depends on the comptability of the 
chromosomes introduced with those already present in the syngameon 
and on the degree of difference between these and the latter. As 
an example of considerable changes so produced I may cite the 
results of the introduction of chromosomes from the syngameon 
Antirrhinum glutinosum into that of A. majus. 
The immediate result of a cross is endless diversity; nature 
immediately begins to play havoc with this diversity, and this 
elimination leads to the isolation of different types. In other words 
nature applies the same principle which man applies in breeding: 
isolation. In this respect DARWIN is perfectly right: the way in 
which domestic races arise is the same as thatin which ,,species” 
arise in nature. There is however considerable difference: man- 
selects — isolates — with a particular end in view: the adaptation 
of the organism to his needs, DARWIN imagined a way by which 
nature could do something similar, to wit adapt the organism to 
its own needs, to the conditions under which it has to live, by a 
process which led to the survival of the fittest. Against this part 
of the parallel between selection by man and by nature a good 


