310 Miscellaneous. 



ment of a parasite, either animal or vegetable, which under certain cir- 

 cumstances attacks alimentary substances, especially pastry, commu- 

 nicating to them a bright red colour resembling that of arterial blood. 



According to the interpretation of several historical facts given by 

 M. Ehrenberg, who has published a very interesting and erudite 

 work upon this production, its appearance in the dark ages must 

 have given rise to fatal errors, by causing the condemnation of un- 

 happy victims to capital punishments, for crimes of which they were 

 totally innocent. It is in fact to this phsenomenon that we must refer 

 all those instances of blood found in bread, on consecrated wafers, 

 &c. which the credulity of our fathers attributed to wdtchcraft or 

 regarded as prodigies of fatal presage. 



On the 14th of July last, I was at the Chateau du Parquet, near 

 Rouen, with M. Aug. Le Prevost : every one knows, that for about 

 ten days at that time the temperature had been exceedingly high. 

 The servants, much astonished at what they saw, brought us half a 

 fowl, roasted the previous evening, which was literally covered with a 

 gelatinous layer of a very intense carmine red, and only of a bright 

 rose colour where the layer was thinner. A cut melon also presented 

 some traces of it. Some cooked cauliflower which had been thrown 

 away, and which I did not see, also, according to the people of the 

 house, presented the same appearance. Lastly, three days after- 

 wards, the leg of a fowl was also attacked by the same production. 



Examining it with a microscope of middling power lent me by 

 M. Le Prevost, I readily convinced myself that it was the same thing 

 which had been observed by M. Ehrenberg ; for a specimen of it, 

 developed upon cooked rice, which had been sent by M. Ehrenberg 

 to Dr. Rayer some years since, had been submitted to ray inspection 

 by that gentleman. 



Whether it be an animalcule {Monas prodigiosa) as M. Ehrenberg 

 thinks, or a fungus {Zoogalactina imetropha) as M. Sette considers 

 it, the individuals composing it are so extremely small that their dia- 

 meter is not more than j~^ of a millimetre, and it requires a magni- 

 fying power of at least 800 diameters to observe them satisfactorily. 

 This parasite is propagated with great facility when sown under 

 favourable conditions, — in cooked rice for example placed between 

 two plates or in closed vessels. M. P. Col, a chemist of Padua, has 

 employed it in tinging silk various shades of rose colour. — Comptes 

 Rendus, xxxv. p. 145. 



IRISH MOLLUSCA. 



To the Editors of the Annals of Natural History. 



Windsor Lodge, Monkstown, co. Dublin, 

 September 16, 1852. 



Gentlemen, — Upon my friend Dr. Battersby showing the speci- 

 mens of Cylichna we took in Birterbuy Bay to Mr. Clark of Bath, 

 he pronounced that the}- were the Cylichna strigella, and not the 

 C. coHulus, as stated in the September Number of the ' Annals.' 

 I am. Gentlemen, yours most truly obliged, 



William W. Walpole. 



