Dee. 2, 1869 | 
NATURE 
T39) 
central belt, which has been for years a pearly-white, is now a 
rich golden yellow. 
Three or four dark markings on the lower part of the southern 
dark belt nearest the equator will be seen to incline to the 
left. 
would appear no larger than these dark masses, so enormous is 
their extent. The rotation of the planet is carrying them towards 
the right : we may assume that the bright vapour between them 
is left behind by the planet, which is here travelling at the rate 
of nearly 3,000 miles an hour. 
South. 
JUPITER, OCTOBER 9g, 1860, 11 P.M. G.M.T. 
Spectrum analysis has taught us to suspect that any change in 
the colour of light proceeding from an object, indicates a change 
in the object itself. If Jupiter, the largest planet in the solar 
system, has still retained so much heat as to shine partially by 
his own light, the present considerable change in colour may 
enable spectroscopists to obtain some information on this inte- 
resting subject. JOHN BROWNING 
Cuckows’ Eggs 
WILL you kindly grant me space for a few remarks in reference 
to the very interesting paper on the eggs of the cuckoo, by 
Professor Newton, in your last issue? I have no intention to 
criticise so able and accomplished a naturalist: my object is 
simply to elicit information on some points of difficulty; and as 
Mr. Newton promises a second paper,‘ I should be very glad if 
he would throw any light on them. 
And first as to the colour and markings of cuckoos’ eggs. Are 
they so variable as some assert? I must take leave to doubt this. 
I never met with such extreme varieties, nor can I hear amongst 
my oological friends of any who have done so. One of the most 
eminent and experienced of living odlogists has stated: ‘* As far 
as my own experience goes, it teaches me that there are not many 
birds the eggs of which differ less than those of the cuckoo.” 
On the other hand, Mr. Newton says: ‘‘It has long been noto- 
rious to odlogists, that the eggs of the cuckow are subject to very 
great variety of colour.” This, then, is a point on which I think 
further evidence is wanting. Dr. Baldamus mentions sixteen 
varieties of eggs which he alleges are cuckoos’. Were these seen 
to be deposited by the bird, or how were they identified as those 
of the cuckoo? Dr, Baldamus does not appear to have taken 
them all himself. Is there not room for error here? 
Mr. Newton saw these eggs, appears satisfied that they were 
~ those of the cuckoo, and agrees with Dr. Baldamus in his con- 
clusions, that the object of the practice was that the cuckoo’s egg 
should be “less easily recognised by the foster-parents as a sub- 
stituted one.” How then is this process effected? Mr. Newton’s 
explanation is that each hen cuckoo deposits her eggs only in the 
nests of one species, that her eggs resemble those of the species 
whose nest she uses, and that this process is hereditary. 
Here it is that I am most in doubt. How is this hereditary 
If our earth were removed to Jupiter’s distance, its disc | 
habit of laying a particular style of egg maintained? It is quite 
possible that habits may become hereditary; but is there any 
| instance of a wild species of animal inhabiting one locality and 
freely intermingling, where some members possess peculiarities of 
habit which are hereditary which their fellows do not? Mr. 
Newton will excuse me for saying, that the Golden Eagle he 
mentions scarcely fulfils these conditions. Is it likely there are 
sixteen varieties of our common cuckoo which are only to be 
distinguished from each other by laying a differently marked and 
coloured egg? Few birds are more vagrant or possess less con- 
Jugal or parental affection than the cuckoo. How then are these 
sixteen varieties to be kept from crossing? And if, as I believe, 
| interbreeding does take place, how can the alleged distinctive 
| style of eggs be preserved? Here I am at fault, and I shall be 
very glad if Mr. Newton will help me out of my difficulty. 
In the face of the alleged object} that the egg shall be less 
| 
. . > ata 
easily recognised as a substituted one, how are we to account for 
the fact that, in this country at least, a larger number of cuckoos? 
| eggs are deposited in the nests of the hedge sparrow than in those 
of any other species, the speckled brown egg contrasting strongly 
| with the greenish blue ones ? 
W. J. STERLAND 
The Corona 
IN connexion with Mr. Lockyer’s paper ‘‘On the Recent Total 
Eclipse of the Sun,” the following observations may be useful. 
I observed the total eclipse of July 1860, in company with my 
| friends Professor Chevallier and Mr. B. E. Hammond, at the 
| village of Pancorbo, in Spain. We were on the summit of a 
mountain of considerable height, about 5,000 feet above the sea, 
| and were therefore under somewhat peculiar atmospheric con- 
ditions. I observed specially four things :— 
(1) Venus ; which was then extremely near the sun, the 
thickness of the crescent being only 1 or 2 seconds, and therefore 
very favourably placed for observing whether it has an atmosphere. 
| (2) The extent of the corona, and its form. This Iam sure was 
very irregular; very nearly, if not quite, permanent during the 
three minutes of totality; was nowhere less than 25’ in breadth ; 
in one part, the top in an inverting telescope, 40’ in breadth; and 
in another, the right, was more than 60’ in breadth, running out 
in a long wavy line like floss silk. Ihave before me the drawing 
I made at the time, during the totality. 
(3) The amount of light given by the corona. This was 
estimated by a photometer, consisting of a wedge of dark glass, 
with a moveable slit, contrived by Mr. Chevallier, and now, I 
believe, in the possession of the Astronomical Society, with the 
place marked through which I saw the corona. It was as bright 
as a small cloud, distant 8° from the sun, 10 minutes after 
reappearance ; or as the moon when 24 days old, as the sun was 
setting. 
(4) The colours shown by a variety of coloured ribbons during 
totality. Of these, the only observation that bears on Mr. 
Lockyer’s paper, was that on the extent of the corona. I 
estimated it twice ; once as reaching, to the right, 2¢ diameters of 
the sun,“and once, later on, at nearly 24 diameters. I had no 
micrometer, but could not possibly have,been wrong by so much 
as 10’. I wrote down at the time, that it underwent no perceptible 
change during the eclipse. It remained visible for six seconds 
after the reappearance of the sun. 
I had, and have, little doubt that the corona is in the solar, and 
not terrestrial atmosphere. 
Rugby School, Nov. 11 
JAMEs M. WILsoN 
Lightning in a Clear Sky 
WE constantly find allusions in ancient classical authors, to 
lightning and thunder occurring in a clear sky. The former is 
often explained as referring to the phenomenon commonly known 
as ‘‘summer lightning,” or the reflection in the sky of lightning 
from clouds below the horizon, which becomes visible at night. 
I have also seen it stated that in the calm and clear atmosphere 
of Italy, thunder might be audible under similar conditions. 
These explanations, however, do not meet the case as stated by 
good observers amongst the ancients themselves. They do not 
explain, for instance, what is stated by Cicero amongst the 
portents which preceded the conspiracy of Catiline—‘‘that a 
Roman citizen was killed by lightning on a cloudless day.” Pliny 
also mentions this case, adding that it happened at Pompeii. 
If such a phenomenon as lightning, falling from a cloudless sky, 
is disbelieved by men of science, may not the circumstance stated 
above be explained by supposing the man to have been killed by 
