' Prof. Parsons on the Origin of Species. 9 
now comes and declares it to be all a great mistake. He doubts 
whether any one shell of the 4 per cent, the 17, the 40, or the 
90, has ever been looked upon alive by man. 
Far be it from me to undertake to decide between such men. 
But again let me draw one conclusion, whic seems certain; 
and it is that there is no sure, unerring, and unmistakeable test 
of specific identity or difference. 
{we admit with the qualification and in the way above stated 
the theory of the production of all things by generative devel- 
te and the active operation of this principle of the “strug- 
gle for life,” and admit also Agassiz’s requirement of new crea- 
tions, and of the orderly succession and coordination of these, we 
havea theory composed of elements which certainly do not now 
Oppose and destroy each other, but coéxist in harmony, and in 
mutual support and illustration. i 
How far shall we carry it? Not to the creation of all things 
from one beginning, unless farther investigations should remove 
the immense difficulties which this theory must now encounter, 
and sustain its probability. But let not the investigation be 
clouded, obstructed and defeated by the assertion that any the- 
ory which ealls into being all existing and extinct organisms 
true, and must needs be false and dangerous. 
The great difficulty to most minds would be, after all, that 
_ that has ever been born of woman. At first a nucleated cell, 
(call it a monad if you like,) not distinguishable from other nu- 
rs cleated cells, which, by segmentation, gives rise to that germinal 
