THE DARWINIAN HYPOTHESIS 19 
f offspring, which will of course tend to pabeaies | ( 
the peculiarities of their parents. Their offspring | : ns } 
will, by a parity of reasoning, tend to predominate | fyb! 
over their contemporaries, and there being (sup- 
pose) no room for more than one species ae as 
FA. the weaker variety will event entually be de estroyed 
by the new destructive influence which is thrown 
into the scale, and the stronger will take its place. 
p Surrounding conditions remaining unchanged, the, 
“new variety (which we may call B)—supposed, for 
argument’s sake, to be the best adapted for these 
conditions which can be got out of the original 
- stock—will remain unchanged, all accidental devia- 
tions from the type becoming at once extinguished, 
as less fit for their post than B itself. The tend-, 
- ency of B to persist will grow with its persistence) % 
_ through successive generations, and it will acquire | 
all the characters of a new species. 
- But, on the other hand, if the conditions of life 
3 Benge in any degree, however slight, B may no 
yg longer be that form which is best adapted to with- 
_ stand their destructive, and profit by their sus- 
taining, influence ; in which case if it should give 
rise to a more Pangetonk variety. (C), this this will take 
its place and become a new species ;-and thus, by 
natural selection, the species B and C_will be-sue= 
~“cessively derived from A. 
| eens mastincsamas hypothesis enables us 
_ to give a reason for many apparent anomalies in 
the distribution of living beings in time and space, 
7 C 2 
