164 
36 hours. During daylight on the 23rd there was an Aurora 
Borealis which continued till 1 A.M. of the 24th ; at 7 A.M. rain 
commenced. 
Highfield House Observatory, June 24 E. J. Lowe 
(3.) Seen near Burton-on-Trent, Fune 23. 
The rare and beautiful phenomenon of parhelia was seen 
by many observers in this neighbourhood at about seven 
o'clock on the evening of the 23rd inst., and it continued to be 
visible for more than a quarter of an hour. 
The horizontal bar of light, the coloured halo, and the inten- 
sified light at the intersections, as also a portion of the upper bow, 
were all seen very distinctly. The temperature of the atmosphere 
at the time was rapidly lowering, and during the night a con- 
siderable quantity of rain fell. 
I presume that the phenomenon was very local, as I have seen 
no notice of its occurrence in any of the daily papers to which I 
have had access. 
Burton-on-Trent, June 25 EDWIN BRowNn 
Natural History of Celebes 
Tt will be, perhaps, not without interest to the readers of your 
periodical to receive the information that I am_ leaving for 
Celebes, on a natural history expedition, at the beginning of 
July, to stay there for a considerable time with the purpose of 
exploring first this interesting and little known island as far as 
possible, and this done, the islands in the neighbourhood. 
I shall be happy to learn the wishes and supply the desiderata 
of any naturalist who takes a special interest in the fauna or flora 
of the island. Letters will reach me Poste Restante, Menado, 
Celebes. 
I have just finished the translation and publication of Mr. 
Wallace’s ‘* Contribution to the Theory of Natural Selection.” 
ApOLF BERNHARD MEYER 
12, Victoria Road, Kensington, London, W., June 28 
Fertilisation of the Barberry 
C. K. SrrENGEL, in his Lutdechte Geheimniss der Natur im 
Bau und in der Befruchtung der. Blumen, gives an excellent 
account of the structure of the Common Barberry, Berderis 
vulyaris, and points out how it is visited by insects, and how, 
upon the touch of an insect's limb or proboscis, the irritable 
filaments move inwards, and press the opened anthers against 
the stigma. It is needless to recapitulate the details of structure 
and movements of a plant so well known, but I venture to think 
that there is a function and a purpose beyond those which 
Sprengel’s ingenuity has pointed out. Sprengel’s great object 
was to show how insects and flowers mutually help one ancther, 
and, consequently, when he had shown that the anther could not 
shed its pollen on the stigma until the filament was touched by 
an insect, and that, when so touched, the open anther became 
pressed against the stigma, he was satisfied. He does not seem 
to have been fully alive to the wider generalisation made by 
Mr. Darwin, that this relation of insects to flowers serves the pur- 
pose of crossing by fertilising the stigma of one flower with 
pollen taken from another. At any rate, in this case he has 
been content with the ingenuity of the apparatus for self- 
fertilisation through the instrumentality of an insect. 
But there are one or two circumstances which seem to show 
that there is something further in this curious motion of the 
stamens of the Barberry. 
In the first place, each filament only moves when touched at 
a particular spot near its base, where a very slight touch—e.g., 
with a human hair—will make it start up. The other stamens 
remain unmoved, and a bee will frequently visit the flowers and 
carry off the abundant nectar without moving any stamen at all. 
In the second place, after the stamen has moved inwards, which 
it does rapidly and witha sort of jerk, it soon begins again to 
move slowly outwards and backwards, and in a short time 
recovers its original position. Pollen still remains in the anther 
cells, and the stamen is ready again to jump up towards the 
stigma on the visit of another insect. 
Now these two facts are not explained, if the sole object of 
the movement of the stamens is self-fertilisation. Why in that 
case should each stamen move separately when gently touched 
on its inner side, and why should it return to its original place, 
instead of remaining with its whole mass of pollen firmly pressed 
NALOUREY 
[ Fune 30, 1870 
against its own stigma? Why, too, should it move inwards 
rapidly, and retreat slowly ? 
But if the object be to enable the insect to carry pollen to 
another flower, these facts, as well as the remarkable points of 
structure and function noticed by Spreigel and others, are all 
explained. 
The separate stamen moves when touched on its inner side 
by the thin proboscis or limb of an insect, in such a way as to 
leave its pollen on that limb or proboscis, or on the body 
of the insect, which will then generally be interposed be- 
tween the anther and the stigma. And the stamen returns to 
its place after the insect has departed laden with pollen to other 
flowers, in such a way as that, when more nectar has been 
deposited and another insect comes and touches it, it may again 
spring up and deposit some of its remaining pollen on that 
insect, to be again carried by it to fresh flowers. 
If this be so, the function of the whole apparatus is not to 
cause self-fertilisation, but to enable insects to carry pollen from 
one flower to another. The case is curious, because -at first 
sight the very remarkable movement of the stamens in this plant 
certainly looks like an ingenious device for sel/-/ertilisation, and 
as such, an argument against the crossing theory. 
Mr. Darwin, to whom I have mentioned this, tells me in con- 
firmation, that the North American Barbervies (1/a/onia) have 
become so much crossed that it is almost impossible in this 
country to procure a true specimen of the two or three forms 
originally introduced. T. H. FARRER 
The Corona 
I po not think Dr. Gould's lucid account of his own views 
could have been misunderstood. I, at Jeast, who replied to 
him, understood him in the sense in which he has written to you. 
The chief question at issue has been, whether there is or not 
anything at the sun (to use Dr. Gould’s expression, as, on ac- 
count of its very vagueness, most suitable), outside the prominences. 
Mr. Lockyer has said zo; I and others have said yes; and Dr. 
Gould has helped to prove we were right. It has always seemed 
to me, however, that the photographs taken by Mr. De La Rue 
and Fr. Secchi, in 1860, had settled the question. 
The question relating to matter outside this brilliant appen- 
dage, is of less moment. We know certainly that during totality 
there is some light in our atmosphere, and the question where 
this begins or ends is more interesting to the meteorologist than 
to the astronomer. But I would invite Dr. Gould’s attention to 
the fact that in the March number of the Astronomical Society’s 
Monthly Notices, I have given a simple mathematical proof of 
the fact that no atmospheric light ca come in any considerable 
total eclipse from any’ region of the sky within seven or eight 
degrees of the eclipsed sun. 
So far as this proof is concerned, I cannot admit that the 
matter is one of theory at all. But my views as to the nature 
of the material producing this coronal light are not founded on 
absolutely certain evidence, though the evidence in their favour 
is very strong indeed. Moreover, I should expect that precisely 
those appearances would be seen which Dr, Gould regards as 
tending to show that the faint coronal light arises from some- 
thing which ts not at the sun. 
But really where a mathematical demonstration ot a fact is 
extant, the consideration of arguments derived from admittedly 
doubtful evidence seems a mere waste of time. It may asreadily 
be shown that the three angles of a triangle are not equal to two 
right angles, as that in the Indian or American eclipses atmo- 
spheric glare could have been visible within seven or eight 
degrees of the eclipsed sun. 
In the supplementary number of the Vofices of the Astrono- 
mical Society, I hope to give a further explanation of the extremely 
simple proof on which my views depend ; and (because all ques- 
tions involving considerations of tri-dimensional space <re per- 
plexing to most non-mathematicians) I am having a mechanical 
figure constructed to make the matter clearer, in illustration of 
papers I hope to read at the next meeting of the British Associa- 
tion, and next November before the Astronomical Society. 
RICHARD A. PROCTOR 
South Lambeth, June 24 
Euclid as a Text-book e 
THE suggestion of Mr, Levett with regard to the formation of 
an Association for securing a general reform in the teaching of 
geometry, is worthy of be’ng at once carried out, Such an 
