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. Guerin 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 

 oeconomizcd, 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 a 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 difl'erent 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 

 phfEuomena 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, difl'ers, 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 Hdjntaux, 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 follomng 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 1 0th of March 1847, by a very numerous body of 



