May 12, 1870] 
NATURE 
as 
M. Coquand’s memoir can hardly fail to be welcomed as 
a valuable addition to our paleontological and geological 
literature, both for what it is, and for what it suggests. 
Monographs of the fossils of any one country can only be 
regarded as so many JZémozres pour servir—words and 
lines, rather than pages—of the geological record. In- 
complete as that vast history must ever remain, it would 
be found far more available than it is if we could have a 
synopsis like the present of every important genus. Owing 
to their wide range, and the usually good state of preser- 
vation in which they are found, the study of these fossils 
cannot fail to be of value with reference to some ques- 
tions of much present interest. As compared with the 
fauna of the Cretaceous seas, the fossil mammals of the 
Quaternary period, to which reference is so often made 
in these discussions, afford but very imperfect materials 
for testing the various theories which are from time to 
time put forward as to the succession of species. These 
Quaternary beds usually exhibit but broken fragments— 
disjecta membra, which, while lying on the surface, or 
tossed about in company with river or deluge gravels, 
have been subjected to so many chances and changes 
that the order of succession is often difficult, if not im- 
possible, to ascertain; while, on the other hand, the 
fossils of the chalk, slowly accumulating during countless 
ages in the quiet depths of their seas, exhibit the exact 
order in which their multitudinous genera and species 
successively made their appearance and, having endured 
for their appointed seasons, finally disappeared. 
If we could have monographs of other important families 
arranged upon a plan as comprehensive as M. Coquand’s, 
how much less unsatisfactory might our speculations be 
upon the perplexed and perplexing questions of the origin, 
distribution, and extinction of species. When we con- 
sider the subjects of this memoir, their great variety 
and wide dispersion, although we might perhaps think 
it possible that, as we have heard, an oyster should be 
“ crossed in love,” we find it difficult to imagine the crea- 
ture as existing under such conditions that one species, 
while engaged in “the struggle for existence,” should starve 
out and extinguish another ; or that any process of “ natu- 
ral selection” should avail to alter the formation of the 
hinge as well as the internal and external structure of the 
shell. Indeed, if any such change did occur, it must have 
been er saltum, since with these mollusks, numerous as 
they are, there are no forms that can fairly be recog- 
nised as transitional ; for just as each zone or region of the 
chalk is marked by the presence of its peculiar fauna, so 
each species of this numerous family has a character of 
its own ; it is saz generis, apparently without ancestors 
and without descendants. If, indeed, all the members 
of this great family, by virtue of some law or process of 
evolution, did descend from one common ancestor, we 
should expect to find their forms varied and numerous, 
instead of being, as to our sorrow we find them, 
more simple and far less numerous; so that instead 
of being permitted to choose from the two hundred and 
fifty-five kinds described by M. Coquand, we are reduced 
to the pitiful allowance of one poor “xa¢cve,” and from 
what we see and hear of /z# it seems not unlikely that 
he is to be the last of his race, and that ere long, Oysters, 
like Mastodons will be things of the past. 
J. W. FLOWER 
OUR BOOK SHELF 
Mrs. Loudon's First Book of Botany, for Schools and 
Young Persons. New edition, revised and cnlarged. 
By David Wooster. (London: Bell and Daldy, 1870.) 
WE wish we could speak more favourably of this prettily 
got-up little book. Mrs. Loudon’s writings did good service 
in cultivating a love of plants among the last genera- 
tion ; but when a new edition of an old manual is brought 
out, with the date of the current year on the title-page, 
; and an editor’s name as having “revised” it, we expect 
| that it will be corrected by the light of the present state 
of scientific knowledge. In the present instance this has 
not been adequately done; of the inadequacy we may 
give but two instances. At p. 18 prickles are described 
as metamorphosed leaves, instead of, as they really are, 
indurated hairs, or processes of the epidermis. But a 
more serious erroneous description occurs in the case of 
the spores of ferns, which are said to differ from seeds 
“in not requiring to be fertilised by pollen” (do seeds 
require to be fertilised by pollen?) The reader is left to 
suppose that the young fern-plant springs direct from 
the spore, no reference whatever being made to the 
recent discoveries of the functions of the ~ro-thallium, 
archegonia, and anztheridia. The arrangement is good, 
as also are some of the illustrations ; but the book cannot 
be used as a manual by teachers or lecturers, without the 
errors being corrected from some other handbook. 
A. W.B. 
The Birds of Asia. By John Gould, F.R.S. 
THE twenty-second part of this magnificent work has just 
been issued to the subscribers. It contains fifteen plates 
coloured by hand, including the great alced, four owls, 
two pheasants, three buntings, three piculets, Franklin’s 
barbet, and the long-billed wren, accompanied by letter- 
press descriptions. Among so much that is beautiful and 
interesting, it is very difficult to particularise ; but we can- 
not help referring to the charming little owlet dedicated 
to the late Sir Benjamin Brodie, the eminent surgeon, and 
named Azthene Brodie. Among the peculiarities of the 
bay owl found in Nepaul and the northern confines of 
India, Mr. Gould notices its friendship for wild animals, 
living on good terms with the tiger, and sometimes alight- 
ing on its back. We learn that one of the pheasants, the 
Chinese Crossoftilon, or Dallas’s eared pheasant, is now 
domesticated in our Zoological Gardens ; also that some 
eggs have been hatched there, and that female birds may 
be purchased for 157. The long-billed wren (Rzmaztor 
malacoptilus, Blyth), a small reddish-brown bird, with 
a droll apology for a tail, is said to be excessively rare, 
and one of the most curious and highly-interesting species 
in the Indian avi-fauna. 
Zoologie et Paleontologie générales. Par Paul Gervais, 
Prof. d’Anatomie Comparée au Museum d'Histoire 
naturelle de Paris. Premiére Série. 4to. Planches 
50. (Paris: Bertrand, 1867— 69.) 
THIS handsome volume, with its carefully executed plates, 
is, as the author states, an endeavour to make the treasures 
accumulated in the Museum of Natural History available 
for the advance of science. The present part is occupied 
with the consideration of various living and fossil verte- 
brated animals, and is introduced by a long account of 
the arguments, most of them familiar to our readers, re- 
specting the duration of man’s habitation of the earth, 
together with minute descriptions of bones of the animals 
found in various caverns in France. The second chapter 
treats of the Fossils of Armissan (Aude) ; the third of 
animals living at the present time in the French posses- 
sions in the North of Africa ; the fourth of some fossil 
reptiles of the secondary period, especially including the 
archzopteryx ; the fifth and last considers the different 
species of fossil reptiles. 
