May 8, 1873] 
NATURE 
39 
stricted. Outside of England, Germany, and France, very few 
formations have been seriously studied ; almost the only success- 
ful explorations have been in railway-cuttings. One indication 
of what maybe discovered elsewhere is furnished by the remarkable 
petrifactions which have resulted from some researches prosecuted 
in Africa and Asia, in the neighbourhood of the Cape, and on 
the Himalayas : forms have been discovered which fill up im- 
portant gaps in palzontological classification. It must be remem- 
bered also that only the hard and solid parts of organisms have 
been preserved, that entire forms, such as the Medusz, shell-less 
molluscs, many articulata, nearly all worms, could leave no trace 
behind. The most important parts of plants, the flowers, have 
completely disappeared. Moreover, terrestrial organisms have 
been petrified only in accidental instances, where they have fallen 
into the water and been covered with mud ; it is not to be won- 
dered at then if the number of fossils of this kind is relatively 
much less considerable than that of those kinds which have in- 
habited the sea or fresh water. This explains also the appa- 
rently strange fact that of many fossil mammals, especially those 
of the secondary, we recognise only the lower jaw. This arises 
from the fact that that bone is easily separated from the dead 
body ; while the rest swims on the surface of the water and is 
carried to the bank, the jaw falls to the bottom, and is buried in 
the mud, where it is petrified. The traces of those which have 
been found in different beds of sandstone, and especially in the 
red sandstone of Connecticut, belong to organisms whose bodies 
are entirely unknown to us, and prove that we are far from pos- 
sessing remains of all actual forms. What gives us reason to 
think that an immense number must remain unknown is the fact 
that of those whose fossil remains we possess, only one or two 
examples have come to light. It is only ten years since a bird 
of the highest importance was discovered in the Jura ; till then 
no intermediate form was known between the birds proper and 
reptiles, which are, nevertheless, the class most closely related | 
to the former. Now ‘this fossil bird, which possesses the tail, 
not of an ordinary bird, but of a lizard, confirms the hypothesis 
that birds are descended from the saurians. A couple of small 
teeth which have been found in the Keuper of the Trias are, up 
to the present, the only proof that mammals have existed from 
the Triassic period, and that they did not appear only in the 
Jurassic period, as was previously believed. 
Fortunately we are able to supplement the insufficient data of 
palzontology by tho-e of embryology, since individual develop- 
ment is, as it were, a reproduction or recapitulation brief and 
rapid, by means of heredity and adaptation of the development 
of species. Embryology is especially valuable for the light 
which it throws on the more ancient forms of the primordial 
period ; by it alone do we learn that these primitive forms must 
have been simple cells, similar to eggs; that these cells, by their 
segmentation, their conformation, and their division of labour, 
have given birth to the infinite variety of the most complicated 
organisms. 
To the valuable data respecting the relations of organisms 
furnished by palzeontology and embryology must be added those 
derived from comparative anatomy. When organisms, whose 
exterior is very different, resemble each other in their interior 
construction, we may conclude with certainty that this resem- 
blance is due to heredity, while the differences are a result of 
adaptation. If, for example, we compare the limbs or extremi= 
ties of different mammifers, the arm of man, the wing of the bat, 
the anterior members of the mole adapted for digging, those of 
other mammifers made for leaping, climbing, or running ; if we 
consider, besides, that in all these members variously formed, the 
same bones are found, equal in number, in the same place, dis- 
posed in the same manner, are we not forced to admit the close 
relationship of organisms? This homology can be explained 
only by heredity, by descent from common ancestors. And to 
go still further, if we find in the wing of the bird, in the 
anterior members of reptiles and amphibia, the same bones as 
in the arms of man, or in the anterior limbs of other mammifers, 
can we not affirm with certainty the common descent of all 
these vertebrate animals ? 
SCIENTIFIC SERIALS 
Ocean Highways, May.—The first paper in this number is an 
article on Mexico, by Mr. Maurice Kingsley, accompanied by a 
map showing the course of the Vera Cruz and Mexico Railway. 
This is followed by a very interesting article on “* Railway Com- 
munication between London and Calcutta,” with a tap showing 
the proposed line from Ostende, by Vienna, Constantinople, 
Diabeker, Herat, Cabul, Lahore, Delhi, Cawnpore, and Cal- 
cutta. By this route the land journey would amount to 6,336 
miles, with only 73 miles of sea, which could’ be accomplished 
in 214 hours, or about 9 days ; while by the present shortest 
route, the sea-journey amounts to 3,941 miles, and the time 
taken is 492 hours, or upwards ef 20 days. Dr. Robert Brown 
contributes a paper entitled ‘* A Cruise with the Whalers in 
Baffin’s Bay,” which is followed by ‘‘ Notes on Mr. Stanley’s 
Work,” by Capt. RF. Burton, in which that gentleman points 
out several things in Stanley’s book that he thinks are capable 
of amendment. Burton thinks Stanley ‘‘ wants only study and 
discipline, to make him a first-rate traveller.” This is followed 
by a very valuable paper on ‘“‘ The Steppes to the North of 
Bokhara,” by A. Vambéry. Then follow the usual reviews, 
notes, reports of societies, &c. 
SOCIETIES AND ACADEMIES 
LONDON 
Chemical Society, May 1.—Dr, Odling, F.R.S., president, 
in the chair.—Dr. H. Sprengel, ‘f On a new class of explosives.” 
gave an account of some new explosives consisting of two liquids 
inexplosive by themselves, but which when mixed and fired with 
a detonating charge are as eff-ctive as nitroglycerine. —Prof. Abel 
of the Royal Arenal, Woolwich, drew attention to the great 
difference produced by variations in the mechanical state of the 
explosive.—On Zirconia, by Mr. J. B. Hannay.—On Pyrogallate 
of lead and lead salts, by Mr. W. H. Deering. 
Royal Horticultural Society, April 16.—General meeting, 
Sir Coutts Lindsay, Bart., inthe chair. The Rev. M. J. Berkeley 
commented on the plants exhibited, and remarked that :he unused 
archways of railways might be profitably employed for the produc- 
tion of mushrooms.—Mr. W. A. Lindsay (the secretary) enume- 
rated the concessions which the Council had made for this year to 
Her Majesty’s commissioners for the Exhibition,including a passage- 
way across the gardens: the society would receive in return the 
sum of 1000/.—Scientific committee—Prof. Westwood, F.L.S., in 
the chair. The Rev. M. J. Berkeley commented on an article 
in the recent number of the journal of the Royal Agricultural 
Society on the injury suffered by horses fed upon mouldy oats. 
There was an evident error with respect to the fungus figured as 
Aspergillum (sic) which was clearly the common bread-mould 
Ascophora Mucedo. With respect to the diseased coffee-plants 
from Natal brought forward at the last meeting he was disposed 
to think that climatic conditions were the cause, of their malady. 
The differences between the summer and winter temperatures 
had been too slight to check the growth of the coffee trees. 
There are often three flowerings instead of one, or at all events 
two. It seemed on the whole probable that growth was over- 
estimated, and that, consequently, when the drought came, the 
plants were unable to supportit. There was a minute immature 
black fungus, which might be referred to Defazea, on the twigs. 
Prof. Thiselton Dyer read a letter addressed to Dr. Hooker 
from Dr. Henderson in charge of the Calcutta Botanic Garden, 
describing the disease of the opium poppy. This appeared to be 
favoured by moist weather, and the plants affected were infested 
with Peronospora arborescens, and also with a fungus (which Mr. 
Berkeley identified as Macrosporium cheiranthi, a peculiar form 
of Cladosporium herbarum.) The places attacked were black, 
and the disease progressed from below, upwards. If the plant 
has not flowered when attacked, it never does so; but if it is on 
the point of flowering. the sepals, petals, and stamens, do not drop 
off as they would do in healthy plants. The effect of guano, even 
in very small quantities, was remarkable in increasing the crop. 
Institution of Civil Engineers, April 29.—Mr. T. 
Hawksley, president, in the chair.—‘‘On the Rigi Railway,” 
by Dr. William Pole, F.R.S., M. Inst. C.E. The object of this 
railway was to convey passengers to the top of the Rigi, a 
mountain near Lucerne, from which there was a view so cele- 
brated as to attract large numbers of visitors in the summer 
months. The line commenced at Vitznau, on the Lake of Lucerne, 
and was about four miles long. The works are mostly formed 
by cutting and benching on the rocky slope of the mountain. 
There was but one short tunnel, and only one iron bridge over a 
rayine, The gauge was 4 feet 83 inches. 
GLascow 
Geological Society, April 10.—Mr. John Young, vice- 
president, in the chair—The chgirman exhibited a specimen 
