426 Miscellaneous. 
So that after the death of the muscardic worm, the blood is filled 
with the thallus in every stage of development. In the latter case, 
crystals of a perfectly definite form are mixed with the thallus ; these 
are products of some chemical reaction, and are undoubtedly the 
cause of the rigidity of the dead body of the muscardic worm. 
By means of abstractions of the circulating fluid, which are very 
easily effected, M. Guérin is able to satisfy himself of the state of 
health of silk-worms, or to predict to the silk-worm cultivator the 
invasion of such and such diseases; and this is useful, especially in 
muscardine ; for by ceasing to feed those worms which are doomed 
to an inevitable death, an enormous quantity of mulberry-leaves are 
ceconomized, and the pecuniary loss entailed by such accident is con- 
siderably diminished. 
The reproduction of the globules of the blood appears to be quite 
new and of extreme importance in a physiological point of view. It 
explains very simply the unequal diameters of the globules of the 
blood of the Invertebrata, and directs us to researches in other species 
‘of this extensive group with a view of ascertaining the same facts, 
and to the Vertebrata themselves to find its analogies. In the latter, 
the perfect uniformity in the globules of the blood might @ priori 
indicate a want of analogy; but, if real, we must first accurately 
determine it ; if it be only apparent, we must discover the truth which 
is still unknown. 
On the other hand, we must bear in mind, that in the Vertebrata, 
the nutritive fluid is met with in different states ; the chyle, lymph, and 
blood. The blood is its ultimate expression, the terminal or perfect 
state ; it is probably not in it therefore that we must seek for these 
pheenomena of degeneration of the globules. Those of the lymph, 
which are colourless and smaller, have long been regarded as an earlier 
stage of them. By a coincidence which is at least remarkable in the 
frog, the triton, and the tortoise, where it has been possible to make 
observations upon the lymph, the size of the lymphatic globules pointed 
out by authors is exactly that of the nuclei of the globules of the 
blood in the same animal; the shape, certainly, differs, but the re- 
lation of size is constant. Lastly, there is a curious fact. connected 
with this question: Schultz, who has observed the formation of 
the area vasculosa in the embryo of birds, states that the nucleus is 
the first part which appears; the vesicle being ultimately formed 
around it.—Gazette des Hépitaux, Feb. 2, 1850. 
BRITISH MUSEUM. 
To the Editor of the Annals of Natural History. 
Sir,—Having been in the habit of continually using the Natural 
History collection in the British Museum, never finding any difficulty, 
and knowing by experience that it is the most completely arranged, 
and far more easy of access than any other collection in the country, 
or on the continent, I was surprised to read in the Report of the 
British Museum Commissioners, the following words as the bases of 
all their observations on the Department :— 
“Being aware from the Memorial presented to the First Lord of 
the Treasury on the 10th of March 1847, by a very numerous body of 
