404 
NATURE 
[ Mar. 27, : 1873 
pared with 22g/odium ; the stamens of Geranium: as compared 
with Zyodium. Where the reduction has been unsymmetrical, 
T suspect it has been due to insect adaptation ; as in di-dynamous 
stamens. 
As soon as decussate leaves are secured, then we possess the 
basis for all ordinary leaf-arrangements. 
Dr. Airy alludes to non-existing orders, 4, 2, 4, 74, but in 
the Jerusalem artichoke the secondary series 4, 1, 2, ;%:, 39s, occurs 
frequently, and arises from the breaking up of ‘‘ tricussate ” 
whorls inan exactly similar manner to the primary series, 4, 4, 
2, &c., arising out of opposite leaves. On the other hand spirals do 
not easily, if ever, return to whorls. 
curiously the above is executed in the Jerusalem artichoke, he 
will see that there is evidently some power at work in the plant 
which, as it were, compels the spiral to form, and to form 
mathematically, will be convinced, Iam sure, that a ‘‘ twist” 
is very far from being the cause—there being none whatever in 
the cases mentioned above ; and further, when whorls break up, 
the leaves are at first quite irregular, but they gradually ‘‘ right 
themselves,” acquire the proper angular divergence, and then 
foim some member of the spiral arrangements to perfection. 
GrEorRGE HENSLOW 
Flight of Projectiles 
In reply to the letter of ‘*‘ W. Hope,” in NarurE of March 
13, I request permission to state that by a szfle formula, I 
meant one that would be easily understood. I did not intend 
the word simple to be taken strictly in its mathematical sense. 
It is easy for Mr. Hope to employ symbols to represent the 
initial velocity, angle of elevation, or any other additional par- 
ticular he may consider necessary fur the solution of my problem. 
No one possessing the most elementary knowledge of the 
theory of projectiles can be ignorant of the disturbing elements 
to which your correspondent refers, or of others to which he 
makes no allusion. But these cannot be accurately estiruated, 
and, therefore, must necessarily be neglected in a theoretical in- 
vestigation. I do not anticipate that they will be found to 
vitiate the results of theory to the extent Mr. Hope supposes. 
In the practical application of the formula for which I have 
asked, the numerical values of the general symbols, would be 
the sean of carefully conducted experiments. Thus the trifling 
variations arising from slight differences in the charge, the 
amount of fouling, or other causes, would be reduced to a mini- 
mum. The variations in the force and d'rection of the wind 
would often neutralise each other. For these reasons I cannot 
agree with Mr. Hope in thinking that the calculation would be 
-either ‘‘useless or deluding,” on the contrary I believe it would 
be valuable as indicating a mean deflection, about which the 
experimental deflections wouid be found to group themselves. 
Of one thing I am certain, that it would enable us to bring 
home to the soldier the great effect of wind in deflecting the 
bullet, and perhaps it might assist us in dispelling the notion of 
absurdity which is inseparably associated in his mind with the 
effort to hit something by aiming at nothing. In accomplishing 
this one of the greatest obstacles to the development of skill in 
rifle-shooting would be removed. , 
If Mr. Hope will kindly supply me with the formula which I 
have asked for, I can assure him that however lightly he may 
appreciate the resulis of his labours, by me, at Jeast, they will be 
valued, and, I venture to hope, made practically useful. Surely 
he cannot be in earnest in denouncing all theory which approxi- 
mates to, but does not exactly accord with practice, as ‘‘ bastard 
science, or pedantry.” If this dictum be sound, I can only say 
it would be easy to show that a great deal of the science of our 
day, gunnery science in particular, is spurious. 
General Didion, a high authority, did not consider my problem 
unworthy of investigation. In the Cours Llementaire De Balis- 
tigue, he has given a solution which I regret is rather too com- 
plicated for my purpose. I should imagine that he would be the 
last person to expect his theory to afford more than a rough 
approximation to the results of practice. Hence I conclude that 
in publishing his calculation for the benefit of the French army, 
he could have had no conception that his science was ‘‘ bastard 
science, or pedantry,” and must have been unconscious what a 
**mischievous unpractical pedant” he was. 
Rosert Rep, Sergeant-Major 
School of Musketry, Hythe, March 17 
Deep Sea Soundings near the Equator 
THE following extract from a letter of the captain of the 
If any one will notice how | 
school-ship AZercury, occupied at present in taking deep-sea 
soundings under the orders of the Board of Commissioners of 
Public Charities and Correction of New York, has been sent to 
me by General Bowen, of that Board, who takes much interest 
in the subject. It will doubtless be gratifying to many of your 
readers :— 
** Our Casella-Miller deep-sea thermometer worked admirably. 
This beautiful instrument steod the test at a depth of 2,040 
fathoms, two miles north of the Equator, in longitude 22° 16’ 
W., when it indicated a temperature of 35° F. ; at 1,000 fathoms 
38°; at 400 fathoms 41°; at 300 fathoms 44°; at the surface 
81°; in the air 80°. 
‘©On our track from the Canary Islands to Rio we found the 
temperatures at uniform depths to vary about 2°. Our speci- 
mens of the bo'tom from the volcanic; region differ in every 
respect from those obtained in other farts of the ocean.” 
Joun Wm. DRAPER 
University, New York, March 6 
SURVIVAL OF THE FITTEST 
HE doctrine of the “survival of the fittest” must be 
strangely understood in some quarters. The 
American papers report Prof. Agassiz as having expressed 
himself in this wise at a recent meeting of the Massa- 
chusetts State Board of Agriculture, of which he is a 
member :—“I do not know how animals originated ; a 
brilliant imagination that of Darwin; a very necessary 
faculty in the scientist. The sense I know too well to 
misquote him, Hasty generalising of observation is 
Darwin all over. Natural selection is out of generation. 
Natural necessity, what is it? Do we find that only the 
strong beget families? Observe plants at the foot of the 
White mountains, where are large trees, and so up to 
the summit, where they are mere shrubs. The weak may 
and do survive as well as the strong. Ignorance lies at 
the base of the discussion.” 
Probably no one naturalist, however eminent, can be 
expected to know everything, or even all simple things. 
Can it be possible that Prof. Agassiz supposes (as 
his argument seems to require) that the dwarf trees 
in question grow and survive near the top of the moun- 
tain, zolwithstanding they are not the fittest, rather than 
because they are the fittest, for the conditions? And does © 
he conceive the doctrine of natural selection to be founded 
upon some idea of an abstract fitness, irrespective of the 
conditions, and not upon the survival of the fittest under 
and in consequence of the conditions? Surely the argu- 
ment brought against the doctrineis a good illustration 
in its favour, only an extremely simple and elementary one. 
We never could quite comprehend why Prof. Agassiz 
should give himself so heartily and persistently to the 
work of demolishing the doctrine of the derivation of 
species, in all its forms, considering how large and 
honourable a part he has himself taken in laying the 
foundation upon which the medern doctrine has been 
built. Of these foundations none is stronger than the 
capital one, generally supposed to be established by him, 
that the succession of species in time corresponds mainly 
with that in systematic rank, and is also somehow 
paralleled in the development of each individual of the 
higher ranks. Sothat, in view of his continued but un- 
successful efforts to drive the incoming doctrine out of 
the land, we could imagine him addressing his own im- 
portant discoveries in the words used by Balak to Balaam ; 
—‘“ What hast thou done unto me? I took thee to curse 
mine enemies, and behoid, thou hast blessed them alto- 
gether.” 
SUB-WEALDEN EXPLORATION.—SECOND 
QUARTERLY REPORT 
A FRESH survey of the Lower Wealden beds in eastern 
Sussex by the officers of the Geological Survey De- 
partment has quite recently been made. The whole dis- 
