I THE INTRODUCTION OF NEW SPECIES 17 
necessarily most imperfect and fragmentary,—as much so as 
our knowledge of the present organic world would be, were 
we forced to make our collections and observations only in 
spots equally limited in area and in number with those 
actually laid open for the collection of fossils. Now, the 
hypothesis of Professor Forbes is essentially one that assumes 
to a great extent the completeness of our knowledge of the 
whole series of organic beings which have existed on the 
earth. This appears to be a fatal objection to it, inde- 
pendently of all other considerations. It may be said that 
the same objections exist against every theory on such a sub- 
ject, but this is not necessarily the case. The hypothesis put 
forward in this paper depends in no degree upon the com- 
pleteness of our knowledge of the former condition of the 
organic world, but takes what facts we have as fragments of 
a vast whole, and deduces from them something of the nature | 
and proportions of that whole which we can never know in 
detail. It is founded upon isolated groups of facts, recognises 
their isolation, and endeavours to deduce from them the 
nature of the intervening portions. 
Rudimentary Organs 
Another important series of facts, quite in accordance 
with, and even necessary deductions from, the law now 
developed, are those of rudimentary organs. That these 
really do exist, and in most cases have no special function in 
the animal economy, is admitted by the first authorities in 
comparative anatomy. The minute limbs hidden beneath the 
skin in many of the snake-like lizards, the anal hooks of the 
boa constrictor, the complete series of jointed finger-bones in 
the paddle of the Manatus and whale, are a few of the most 
familiarinstances. In botanya similar class of facts has beenlong 
recognised. Abortive stamens, rudimentary floral envelopes 
and undeveloped carpels, are of the most frequent occurrence. 
To every thoughtful naturalist the question must arise, What 
are these for? What have they to do with the great laws of 
creation? Do they not teach us something of the system 
of Nature? If each species has been created independently, 
and without any necessary relations with pre-existing species, 
what do these rudiments, these apparent imperfections mean ? 
Cc 
