66 
NATURE 
[May 26, 1870 
and yet think we might do something to help forward the good 
cause by co-operating with others. 
ft The immediate objects of such an association should be in my 
opinion (1) To collect and distribute information connected with 
the subject ; (2) To induce examining bodies to frame their 
questions in geometry without reference to any particular text- 
book. RAWDON LEVETT 
King Edward’s School, Birmingham 
Philology and Darwinism 
Mr. Farrar’s interesting communication on this subject 
ina recent number of NATURE, suggests to mea few remarks. 
As one who has paid considerable attention to the various dialects 
existing throughout Scotland, as well as to the manner in which 
our Gaelic-speaking population is by stern necessity obliged 
to attempt the pronunciation of Anglo-Saxon words, I have 
become thoroughly convinced that the growth, life, and death of 
languages are subject to fixed laws. ‘The Highlander whom I 
meet and who tells me this is a ‘‘ Koot tay” is as unconsciously 
obeying Grimm’s law of the transposition of consonants as the 
sun above him is obeying Newton’s law of gravitation. 
There is this difference, however, between Mr. Darwin’s 
teachings regarding animals and the changes of language, that 
whereas those animals whose breeding and training are most 
subject to man’s conscious action exhibit the greatest amount of 
variability, those dialects which are the most neglected and 
despised by educated men, and which, in this respect, may be 
called the weeds of speech, are far more variable than Queen’s 
English, watched over as the latter is by such a host of school- 
masters, lexicons, and grammars. The difference of pronuncia- 
tion of the same words in different counties is great, while many 
words in the dialect of one county are quite unknown in that of 
another, in this respect presenting a striking analogy to the 
Flora of the country. Even in words formed from sound, in 
which case, at first thought, we might expect considerable 
uniformity, the difference is often very marked, as between 
Scotland and England. The words imitative of the animal 
voice, or of the different cries of the same animal under different 
sensations are sometimes unlike, for the horse weighs and the cat 
mews in England, whereas they respectively xicher (ch guttural), 
and zyfoo in Scotland. Sometimés the imitative word is from 
the sound of different organs, as /afzwing in English from thé 
flap of the wing ; feet in Scotland from the sound of the voice. 
Generally people so ignorant as to be necessitated always to 
express their thoughts in a rustic dialect, do so with the assist- 
ance of more or less gesture, and even this gesture is not quite 
whimsical, but has family and county resemblances. In con- 
clusion, my impression is that the dialects which run wild are 
much more variable than those under man’s care, which is the 
reverse of the case with wild and domestic animals and plants. 
S. J. 
Xanthidia in Flint 
Dr. CARPENTER, in his recent lecture at the Royal Institution 
on “the Temperature and Animal Life of the Deep Sea,” speaks 
of the resemblance of the globigerina mud to chalk as being 
‘* greatly strengthened by the recognition of several characteristi- 
cally cretaceous types among the foraminifera scattered through 
the mass of e/obigerine, of which it is principally composed ; as 
also of the Xunéhidia frequently presented in flint. (NATURE, 
vol. i., p. 564.) 
The precise nature of the spinous orbicular bodies found in 
flint, and generally called XNawéhidia, has hitherto been a matter 
of some doubt. Ehrenberg described them as fossil species of 
his genus of supposed polygastric animalcule, Yavthidium. 
Their structure, however, differs in many respects from true 
Xanthidia, which forma genus of Desmidiee, now universally 
admitted to be vegetable organisms, and, like nearly all desmids, 
having compressed bipartite cells, whilst the fossils have globose 
and entire cells. The most recent opinion has been that they 
are the fossil sporangia of other species of Desmidiez, and they 
do indeed bear considerable resemblance to the sporangia of 
various species of the genera Micrasterias, Euastrum, Stauras- 
trum, Cosmarium, and Closterium, An objection to this opinion 
arises from the fact that Desmidise are (so far at least as at pre- 
sent ascertained) exclusively fresh-water plants, and do not ap- 
pear at all adapted for a deep-sea existence; whereas on the 
other hand, the chalk containing the flints may now be said to 
have been conclusively proved to have been formed at a consider- 
able depth at the bottom of the sea: and the other organisms 
with which the fossils in question are found associated are un- 
doubtedly marine. 
The discovexy of these Yanthidia (?) then, at an ocean depth 
of 767 fathoms, is a most important fact, whatever their nature 
may be ; what that nature is, I, and I doubt not many others 
of your readers, would be glad to learn from Dr. Carpenter, or 
others who have had an opportunity of seeing the specimens he 
alludes to. 
Winchester, May 14 FRED. J. WARNER 
What is a Boulder? 
Wir# all terms in ordinary use there is a looseness of mean- 
ing, which, while not in the least degree inconvenient in common 
language, becomes so when transferred to the would-be-exact 
nomenclature of science. 
Hobbes says, ‘‘A name is a word taken at pleasure to serve 
for a mark which may raise in our own mind a thought ; like to 
some thought we had before, and which being pronounced to 
others may be to them a sign of what the speaker had or had not 
before in his mind.” 
Icis obvious, however, that a name pronounced by a speaker, or 
written by an author, can only raise, in the minds of others, the 
proper thought, when the exact meaning of such a name has 
been agreed upon by those who make use of the name ; and it 
appears to me desirable that in all cases when names in common 
use are transferred to the language of science, their exact meaning 
should be stated. In some sciences, as in botany, this is done, 
where such terms as leaf, stem, root, &c., are defined apart from 
their ordinary signification, but much remains to be done in this 
way. Thus, take the query at the head of this letter. I have 
tried to find out exactly what a boulder is, and I completely fail. 
According to Dance a boulder is “a mass of rock, whether rounded 
or not, which has been transported by natural agencies from its 
native bed.” This definition is excellent at first sight, but it 
fails, as the term ‘‘mass of rock” conveys no clear idea as to 
size. Ask half-a-dozen persons the smallest size they would attri- 
bute to a mass of granite, and the answers would vary considerably. 
One cannot see why the smallest piece that would contain the 
constituents of the rock should not be called a mass, and in that 
case many of the large grains of sand on a granitic coast would 
be included in the term ‘‘boulder.” But this is absurd, for we 
might then speak of carrying half a dozen boulders in the waist- 
coat pocket, or a geologist might suffer from having a boulder 
blown accidentally into his eye! There is apparently no de- 
terminate size at which a boulder begins or ends ; butit seems to 
me desirable that some idea of size included should be given in 
the definition, and I would ask some of your readers to be good 
enough to state what they understand by a “boulder,” with a 
view of getting an exact idea of the meaning of this frequently 
used term. j 
Midland Institute, May 9 C. J. WoopwarD 
The Anglo-Saxon Conquest 
A CORRESPONDENT, writing under the signature ‘* A. Hall,” in 
your issue of last week, suggests that in laying certain statistics as 
to the longevity of the Romano-Britons before the Royal Institu- 
tion, I had ‘forgotten that the youth of Romano-Britain had for 
many generations been forcibly expatriated, drafted abroad to 
feed the armies of Imperial Rome.” Your correspondent ‘‘ap- 
pears to have forgotten” what the résumé of my lecture stated, 
viz., that my observations related to the time of Cerdic ; and he 
will now no doubt recollect that a space of about three genera- 
tions intervened between this period and the one to which he 
refers, Less than three generations is a sufficiently long period 
to allow of the balance which the Romano-British population is 
supposed to have suffered by being drafted into the Roman 
armies, righting itself. f 4 
I have, in a memoir which the Society of Antiquarians has 
honoured me by publishing in the ‘‘ Archzeologia” of this year, 
given other reasons, and these at greater length, for holding the 
explanation which your correspondent suggests for my statistics 
to be erroneous. Ido not in that memoir quote, in illustration 
of and as a means of expressing that explanation, some lines 
from Mr. Henry Lushington’s poem ‘‘Inkermann.” These lines 
I did quote in my lecture, and will quote them here, as they may 
