37 
onus probandi rests with them, and no proof has ever yet been 
given. Whereas the possibility of the other view has been 
proved, and the probability of its truth elsewhere derived 
amounts to a moral conviction. 
I would only here add one more remark upon this objection, 
and that is, because well - marked types may and have con- 
tinued unchanged for indefinite periods, that does not contro- 
vert the possibility of their subsequently changing when new 
forces are brought to bear upon them by being in altered 
conditions ; nor does it at all interfere with the doctrine of 
evolution. 
It is worth while here observing that no form of the doctrine 
of evolution can be maintained which does not recognize this 
fact, which has been called a “ Retention of Type ” ; by which 
is meant that co-existent with a gradual evolution of forms of 
life in an ascending scale, there are members of nearly every 
group still living and retaining the characters generally of a 
comparatively lower grade of that group. To say that natu- 
rally less highly organized or complex forms are less liable 
to vary, and are more adaptable to surrounding conditions, 
is to state a palpable fact, and accounts so far for their 
present existence. Such retention of types must, therefore, 
be recognized by every one who holds to the doctrine of evo- 
lution. 
Now, admit the fact of indefinite variation in offspring; admit 
the possibility of a higher, but apparently untraceable, law re- 
gulating the variation with an ultimate purpose, as Mr. Darwin 
does in the passage I have quoted, wherein he says: “ The birth 
of the species and of the individual are equally parts of that 
grand sequence of events which our minds refuse to accept as 
the result of blind chance,” — and you will find no difficulty in 
embracing the doctrine of evolution. Secondary causes, such, 
for example, as natural selection, may be the means of con- 
trolling those variations, favouring some rather than others ; but 
those secondary causes are themselves subject to higher laws, 
which are recognizable when we take in a broad and extended 
view of nature, but apparently absent in a contracted view : 
and it is the contracted view which encourages all ideas of 
chance without a higher and Providential Power. 
The fourth view, or that of the author of this essay, requires 
no further elucidation than is expressed in the terms given on 
p. 4, as he ventures to think each point or element has been 
established in considering those of the other views. 
