226 Experimental Zoology 
Even if the new form is adapted to the same locality as the 
parent species, it may ripen its germ-cells at a different time, and 
this will again increase its chance of isolation from the parent 
species. 
If the new form is only a variety in de Vries’s sense, it will get 
an opportunity of surviving in another way. Suppose it does 
back-cross in the first generation, it will reappear in every succeed- 
ing generation, so that it may go on increasing in numbers every 
year. If it should be a form with better chances of survival 
than the parent, it may subsequently become the more common 
type. 
It has been shown, especially in some animals, that the new 
mutation may dominate in crosses with the parent form. Con- 
sequently, in the next generation it may appear in many indi- 
viduals, and the number of new individuals will increase in every 
generation. Should the new character follow Mendel’s law, 
some of the hybrids will be pure, others mixed ; but in either case 
the opportunity of surviving is given, and if the dominating type 
is at all capable of existing, it will always remain in existence, 
and, under certain conditions, as when, for instance, it is better 
suited than the parent form to another locality, it may establish 
itself there. 
The important experimental results of Standfuss bear directly 
on the problem of the crossing of new mutations with the 
parent species. He describes a number of cases that he has 
himself observed, and records anumber of aberrations recorded 
by other entomologists, in which a new type was crossed with 
the parent stock. A few cases are also given in which two 
aberrations were inbred. In both groups the offspring were 
either like the parent species or like the aberration, and no inter- 
mediate forms were produced. These results were obtained in 
the first generation of hybrids. In a few cases a new genera- 
tion was also reared and the same phenomenon of splitting was 
observed. These results show that a new type that appears may, 
even if crossed with the parent species, reproduce itself in its pure 
form without blending. The process continuing in succeeding 
