REY. JOHN GERARD, F.L.S., ON SPECIES AND THEIR ORIGIN. 13 
result. Animal homologies, we are told, presuppose blood 
relationship ; but this is not so unless blood relationship implies 
animal homologies.” 
Our enquiry therefore comes in the end to this: are the 
resemblances between individuals, plants and animals, accord- 
ing to which we classify them in the same species, regulated 
by some dominating cause, or are they merely fortuitous? As 
Professor Bowne puts it :— 
“The only further question that can arise concerning species 
is whether the power which produces individuals does so at 
random or according to rule. In the latter case species exist 
in the only sense in which species can exist ; that is, natural 
groups exist whose members are bound together by their 
likeness, and the likeness of the members is due to the fact 
that they have been produced according to a common rule.” 
It would, in fact, appear that mere points of resemblance 
between individual objects do not suffice for the establishment, 
of a species, or, which is the same thing, that such points of 
resemblance, if sufficiently numerous and characteristic to 
afford a basis for such establishment, necessarily convey 
the idea of a rule to which such resemblance is due. The 
resemblances to a camel, a weasel, and a whale, which Hamlet 
indicated to Polonius in the shapes of clouds, would never 
sugvest the idea of species, simply because they were obviously 
quite casual, being due to the random operations of the wind. 
On the other hand, were the sky to be filled with cloud 
pictures accurately representing droves of camels or schools 
of whales, we should inevitably conclude that this was 
undoubtedly owing to some sort of rule or cause, even though 
we could form no notion as to what might be its character. 
So, when we find in organic nature groups “of plants or animals 
unmistakably stamped with the same image or likeness, we 
cannot but explain their mutual relationship ; as being the result 
of some common influence—just as in the case of coins or 
books issued from the same mint or printing press. In the 
case of organic species the influence thus manifested is, we 
are told, that of common descent; but, whereas that of the 
coiner or printer is one the nature of which we thoroughly 
understand, of descent we can only say that we know nothing 
whatever as to its mode of operation, nor, indeed, anything 
except the phenomena exhibited by its results—the very thing . 
that has to be accounted for; so that in reality, to explain what 
we would understand, we are bidden to fall back on our lack of 
knowledge. 
