232 
EXTRACTS —N AT URAL IIISTO R Y. 
The fecula and the lignine are of a more permanent nature ; the fecula set 
ties itself as though it were stored in the organs which must ultimately be de¬ 
veloped; it retains the soluble matter, which is protected from the water by the 
insoluble covering that surrounds. 
In short, the lignine is deposited in those particular organs which have reached 
the complete stage of their developement, or in the tissues themselves of the 
vegetable membranes, nor does it appear to be of a nature fitted to be trans¬ 
ferred again to the other parts.— Prof. De Candolle.—Field Nat. Mag. 
Cause or volcanoes.— It is not long since it was thought that the decompo¬ 
sition, and subsequent ignition of pyrites, was sufficient to account for volcanoes, 
&c. though they are rarely if ever found in lava, or volcanic productions, and 
they are still more rarely found at all in masses of any extent. Besides, so long 
as they remain enveloped in rocks, they arc unalterable; and two or three spe¬ 
cies, even under the most favourable circumstances, are decomposable with great 
difficulty; and only one species---radiated pyrites, is capable of being rapidly 
decomposed, but not unless it be broken or crumbled into small portions, and not 
too much, or too little moistened_ M. Cordier, Field Nat. Mag. 
On the temperature of Shallows at Sea. —The waters which cover shoals, 
owe the diminution of their temperature, in a great measure, to their mixture 
with the lower strata of waters, which rise towards the surface on the edge of the 
banks. The proximity of a sand-bank at sea is indicated by the rapid descent 
of the surface temperature of the water. Capt. Williams. Field Nat. Mag. 
Gold-Crested Wren.— -The Golden-Crested Wren, and the common brown 
Wren, are both very impatient of cold. In confinement the least frost is imme¬ 
diately fatal to them. In a wild state they keep themselves warm by constant 
active motion in the day, and at night they secrete themselves in places where 
the frost cannot reach them; but I apprehend that numbers do perish in severe 
winters. I once caught half a dozen wrens in the beginning of winter, and they 
lived extremely well upon egg and meat, being exceedingly tame. At roosting- 
time, there was always a whimsical conflict amongst them for the inside places, 
as being the warmest, which ended of course by the weakest going to the wall. 
The scene began with a low whistling call for them to roost, and the two birds on 
the extreme right and left flew on the backs of those in the centre, and squeezed 
themselves into the middle. A fresh couple from the flanks immediately re¬ 
newed the attack upon the centre, and the conflict continued till light began to 
fail them. A severe frost in February killed all but one of them in one night, 
though in a furnished drawing room. The survivor was preserved in a little cage, 
by burying it every night under the sopha cushions, but having been on one 
sharp morning taken from under them, before the room was sufficiently warmed 
by fire, though perfectly well, when removed, it was dead in ten minutes. Hon. 
W. Herbert's Notes on Birds. Field Nat. Mag. 
