Aug. 18, 1870] 
NATURE 
343 
geometry. Itseems to me, therefore, a successful contri- 
bution to “technical education,” and a valuable and sug- 
gestive attempt, but not altogether a successful one, to 
teach scientific geometry on true principles. The bookis well 
adapted for middle-class schools. It is scarcely worth 
while to notice minor faults, either of the printer, which are 
very few, or of style. But it is really to be regretted that 
a degree should have been defined thus :—“ Suppose we 
have a circumference sufficiently large to be divided 
easily into 360 equal parts, each part is called a degree.” 
A degree is an angle, and this conception ought to be pro- 
minently brought forward. 
J. M. WILSON 
THE Sttzungs-Berichte of the Isis Natural History 
Society of Dresden for the first three months of the 
present year contains, as usual, a great number of short 
communications of more or less interest, and among 
them a few longer notices. Of the latter we may mention 
a note on the “Occurrence of Precious Stones in 
Saxon Switzerland,” by M. A. Stelzner ; a paper on 
“ Diatomacez,” by Dr. Eulenstein; a notice by Count 
Pourtalés on the “ American Deep Sea Explorations ;” a 
paper on the “Course of the Boomerang,” by Professor 
Schneider ; and, especially, a paper (illustrated) by 
Dr. Geinitz, on some “ Fossil Fruits from the Zechstein 
and Coal Measures.” The society has established a sec- 
tion for prehistoric archeology, the first meeting of which 
is here recorded ; its proceedings consisted chiefly in the 
delivery of a long opening address by the President, 
Captain Oscar Schuster. 
WHETHER the inhabitants of Rhenish Prussia and West- 
phalia are at the present moment devoting much of their 
attention to Natural History may fairly be doubted, but 
hitherto they have shown great activity in this depart- 
ment, and the publications of their Natural History 
Society generally contain much valuable matter. We 
have lately received the volume of their transactions for 
1869 (Verhandlungen des Naturhistorischen Vereins, 
vol. xxvi.), in which we find several important papers. 
Kaltenbach contributes the continuation of his valuable 
“Natural History of the German Phytophagous Insects,” 
consisting of an alphabetical list of the principal plants 
growing in Germany, either in a wild or cultivated state, 
with an account of the insects feeding upon each of them. 
Dr. C. Schliiter gives descriptions of numerous fossil 
Echinodermata from North Germany, with good illustra- 
tions on three large plates ; whilst from Mr. F. Winter 
we have a contribution to the knowledge of the crypto- 
gamic flora of the Saar district, now the scene of military 
operations. Another important botanical paper is a con- 
tribution to the flora of the Rhine by Dr. P. Wirtgen. 
In the section of the work denominated the “ Correspon- 
denzblatt” we find a note by Dr. Mohr on the “ Theory of 
Coal,” and in the “ Proceedings of the Natural History 
and Medical Society of the Lower Rhine,” a great number 
of notices upon scientific subjects of all sorts. This latter 
part is published separately for the present year. We 
have received the first number for 1870, including the 
proceedings during January and February. 
LETTERS TO THE EDITOR 
[ The Editor does not hold himself responsible for opinions exbressed 
by his Correspondents, No notice is taken of anonymous 
communications, | 
School Natural History Societies 
In your notice ofthe various School Natural History Socicties, 
you have omitted one, which has been established for more than 
a year, and is now in a very flourishing state. I allude to the 
Clifton College Scientific Society. Unfortunately, no one is here 
to give me any statistics, but I understand that it has seventy 
members, with about twenty more waiting for admission. Mr. 
Percival has built a museum ata cost of 1,500/., which will, I 
believe, be opened next September. T. B. PRESTON 
4, Lanesfield Villas, Durdham Down, Bristol 
August I 
IN the leading article ot NATURE for July 28 (which I have 
just received), you name some of the chief public schools in 
which Natural History Societies exist. I am sorry you have 
omitted to mention Cheltenham College as among that number, 
and conclude the omission arose from ignorance of the fact. 
Perhaps it may be interesting to some readers of NATURE to 
hear that last March, a society consisting of members of that 
College, was founded under the presidency of the principal (Mr. 
Jex-Blake) to whom the college is much indebted for the en- 
couragement of Natural Science as a part of the general educa- 
tion of the place. 
The Society numbers about fifty members, the department 
chiefly worked at present being botany, at which several of the 
boys are becoming tolerably proficient, with a small sprinkling 
of devotees to geology and zoology. 
Our difficulty lies in making meetings sufficiently attractive. 
Original papers, containing original observations, are scarcely 
to be expected from the boys themselves till they have been 
educated to observe ; and in our case the number of masters who. 
take an active part in the society is too few to keep interest alive. 
I cannot, however, doubt, in spite of such difficulties, which have 
been felt (and in some instances overcome) by others as well as 
ourselves, that these societies are sowing good seed of which it is 
not too much to hope the world and science will reap the fruit 
by-and-by. 
Boscastle, Cornwall, Aug. 10 
Our Dublin Correspondent and the Parturition of 
the Kangaroo 
ON my safe delivery, after a good deal of labour, from the 
perils of war, and on my arrival in London from Germany, I 
found your letter, enclosing a copy of Dr. J. Barker’s com- 
munication as printed in your issue of the 14th ult. Dr. Barker 
has, apparently, no fault to find with my report, which, as a 
matter of necessity, could not be otherwise than imperfect. But 
he somewhat loftily criticises the writer of the comments on my 
report, who, in spite of the facetious title given to him by Dr. 
Barker, I believe to be a gentleman of considerable merit, and 
one whose comments on my correspondence appear to be always 
most just. Dr, Barker is right when he states that the late Earl 
of Derby’s father did not observe the facts about the Kangaroo 
which he records ; these were observed by the keeper of his 
collection, but they were placed on record by the Earl and hence 
the mistake. Dr. Barker seems annoyed that he should be made 
to appear as if he adopted the views, the absolute nonsense, of 
the writer whose paper he permitted to be read. Those who 
know Dr. Barker know what absolute nonsense it would be to 
believe him capable of adopting them. Yet, ought he not, as 
chairman, to have repudiated and refuted them? Would it not 
have been well if he had given the members of the learned 
societies, on the occasion in question, the information which he 
now offers to the readers of NATURE, and instead of telling them 
“*that the actual passage of the foetal kangaroo from the uterus to 
the pouch was not yet proyed,” he had told them that the fact ot 
there being such an actual passage had long since been proved ; 
though how the actual transit, whether with the help of the 
mother’s paws or lips, takes place, is still regarded as a matter for 
further observation ; and so, instead of appearing to justify the 
reading of such a paper as the one referred to, he would from the 
extent of his knowledge on the subject, have reflected credit on his 
position, and on the societies to which he belongs, and have made, 
at least, an effort to advance the science he is so zealous for. 
August 13 Your DuBLIN CORRESPONDENT 
The Horse-Chestnut 
I saw to-day in the last number of NATURE, a letter on 
the meaning of the word horse-chestnut. As I do not see 
Nature regularly, Ido not know whether any of your corre- 
spondents have called your attention to the similar use of trmos 
in composition. In case this should have escaped them, I send 
the following extract from Liddell and Scott :— 
