272 
they believe that it can be proved to be inadequate, and 
that we must look to some other innate principle for their 
formation. Mr. Mivart supports his arguments wih so 
much cogency of reasoning, so great a knowledge of ana- 
tomical structure, and so complete an acknowledgment of 
the strength of his opponents’ position, that they cannot 
be disregarded by any one interested in the subject. His 
objections are the more deserving of careful consideration, 
inasmuch as he states that he was himself by no means 
dispos<d originally to dissent from the theory of Natural 
Selection, if only its difficulties could be solved, but that 
he has found each successive year that deeper considera- 


tion and more careful examination have more and more 
brought home to him the inadequacy of Mr. Darwin’s 
theory to account for the preservation and intensification 
of incipient specific and generic characters. It behoves, 
therefore, every Darwinian to satis‘y himself that either 
Mr. Mivart’s premisses or his line of argument is unsound. 
The objections brought forward by the author are 
summed up as fo'lows :—(1.) That Natural Selection is 
incompetent to account for the incipient stages of use- 
ful structures. (2.) That it does not harmonise with the 
co-existence of closely similar structures of diverse origin. 
(3) That there are grounds for thinking that specific dif 
ferences may be developed suddenly instead of gradually. 
(4.) That the opinion that species have definite though 
different limits to their variability is still tenable. (5.) That 
certain fossil transitional forms are absent which might 
have been expected to b: present. (6.) That some facts 
of geological distribution supplement other difficulties. 
(7-) That the objection drawn from the physiological 
difference between “ species” and “ races” still exists unre- 
futed. (8) That there are many remarkable phenomena 
in organic forms upon which Natural Selection throws no 
light whatever, but the explainations of which, if they could 
beattained, might throw light upon specific origination. If 
these objections are not new, they are at least sustained by 
new arguments. They are evidently of very unequal value. 
The third is very difficult of proof or disproof The 
fifth may be true in our present state of knowledge, but 
would be very unzafe by itself as the basis of an argument. 
The first, second, and eighth are of greatest value, and 
are those which Mr. Mivart has most closely woiked out. 
Hitherto the attention of those scientific naturalists 
who have concerned themselves with the intricate prob- 
lems of organic life, has been directed almost exclusively 
to the animal kingdom. This may have arisen from the 
greater attractiveness and practical interest of the study of 
zoology, or from the fact that in the popular mind (and 
we fear the error is not confined to mere “ popular” 
writers) natural history and zoology are considered con- 
vertible terms. Be this as it may, the number of botanists, 
with the illustrious exception of Mr. Darwin himself, who 
look on their science in a philosophic spirit, is lamentably 
stiall. We believe, however, that more light will be found 
to be thrown on the problem of the genesis of species by 
a consideration of the phenomena of the vegetable than 
of theanimal kingdom. Plants have less power of adapt- 
ing themselves to new conditions, or of finding for 
themselves more congenial surroundings, than have 
animals. Their locality and their food are, as it were, 
prescribed for them by the circumstances of their birth ; 
here, therefore, we might expect to find the rule of the 
survival of the fittest to reign supreme. We believe, 
however, it would be very difficult to substantiate any 
instances of species of plants being supplanted by other 
closely allied species, similar to those well-authenticated 
in the case of the rat and the cockroach. Plants when 
first artificially introduced into a new country undoubtedly 
frequently spread with extraordinary rapidity, to the de- 
struction of weeds belonging to native races ; but this is 
evidently not the mode in which species have supplanted 
one another in a state of pure nature. 
Under Mr. Mivart’s first head, he deals with the subject 
NATURE 


[Feé. 2, 1871 

of Mimicry, contending that Natural Selection is incom- 
petent to account either for the first or last stages of 
such wonderful instances of protective resemblanceas that 
represented in our illustration. As this subject hasbeen so 
recent'y discussed in these columns, we need not dwe!l upon 
it further than to remark, that we think the author could 
have supported his case with arguments of even greater 
force, had he extended his observations to the vegetable 
kingdom. The only object which it has been conjectured 
can be gained by a plant imitating a different species or a 
foreign structure, is to attract insects to assist in the dis- 
tribution of its pollen. The most remarkable instances of 
the imitation by plants of foreign objects is in the case of 
the curious resemblance of the flowers of certain orchids 
to insects and other animals. One of the most singular 
of these is the well-known bee-orchis. But,as Mr. Mivart 
remarks, Mr. Darwin, in a course of observations extend- 
ing over a serics of years, has never seen a bee alight 
on this orchis. The most noteworthy resemblances again 
of plants zz¢ey se unconnected with organic affinity, are 
not in the flowers, where they might be useful, but in the 
leaves, or in the whole stem and foliage It is difficult to 
conjecture any advantage that is gained by the close re- 
semblance between an African Euphorbia and a South 
American Cactus, the imitation being carried out in the 
most extraordinary manner throughout the vegetative 
organs, the flowers being, of course, totally unlike. 
But besides these superficial resemblances, there are 
also analogies of organic structure in diffzrent classes of 
the animalkingdom, which Mr. Mivart holds to be equally 
opposed to the theory of Natural Selection. He refers 
especially to the existence of the higher organs of sense, 
as the eye, in at least three distinct and independent lines 
of descent, the Mollusca, the Annulosa, and the Ver- 
tebrata, an objection already pointed out by Mr. Murphy ; 
to the resemblance between the shells of certain Mollusca 
and Crustacea, the valve being moved in each case by 
analogous muscles ; to the analogy between the different 
families of Marsupials and the aiferent orders of Pla- 
cental Mammals ; andto numerous otheyx instances. These 
might be supplemented in the vegetable kingdom by the 
similarity in the mode of opening of the anthers in Ber- 
beridaceze and Lauracee, or the extraordinary resemblance 
of certain Conifers to flowerless plants. The wood-cuts 
which we give illustrate the remarkable resemblance be- 
tween an ordinary European mouse and an Australian 
marsupial (Fig. 2); the structure of the cuttle-fish with 
the brain, cartilaginous cranium, and complex auditory 
nerve, presenting so many similarities to those of the 
higher Vertebrata, and yet belonging to a different line of 
descent (Fig. 3); and the cuious bird’s-head-like pro- 
cesses found in some of the higher Polyzoa (Fig. 4) 
Of exceptional structures, none is more interesting in a 
philosophical point of view than the neck of the giraffe. 
This has been explained on Darwinian principles from 
the occurrence in its native country of occasional periods 
of drought, during which those giraffes only have survived 
which had the power of reaching somewhat higher 
branches of the trees ; and this peculiarity, being advan- 
tageous, was propagated, and continually augmented 
during each period of drought by the process of Natural 
Selection. To this Mr. Mivart objects, firstly, that if 
this explanation is correct, many other African animals, 
which have no greater power of endurance or of migra- 
tion than the giraffe, ought to have elongated necks ; and 
secondly, that in the intervals between the droughts the 
long neck would be a positive disadvantage, as requiring 
a greatly increased size and strength of muscles to support 
it, and would, consequently, be lost before the next drought 
setin. To take another instance of the commencement 
of an organic structure which is universal in all the higher 
classes of animals; there is scarcely anything more in- 
explicable than the separation of the sexes, if we suppose 
animals with distinct sexes to have originated by the pro- 
" 
