R. Wagner, (Ch. Gazette, vol. 9, p. 306,) transplanted the recently removed testicles of rabbits and frogs into the abdominal cavity of fowls; the testicles of fowls into other fowls and pigeons, those of pigeons into fowls, and fresh crystalline lens into fowls and pigeons which were killed after ten or fifteen days. The testicles of frogs contained three per cent. of fat, which was augmented to 5.15 per cent. In one case the crystalline lens, after the experiment, contained 47.86 per cent. of fat; in a number of other experiments on lenses, the result was of from 7 to 15 per cent. of fat, calculated for the dry substance of the lens; carefully cleaned portions of frog intestines filled with coagulated blood of pigeons and calves, fat free muscle from the thigh of a frog, and boiled white of hen’s egg, in similar conditions, all gave fat. These experiments were repeated by Husson and Burdach,[3] enveloping the nitrogenized substances in bags or coatings of gutta percha, caoutchouc and collodion. They found the substance well preserved, but no change into fat; so that admission of the animal juices must conduce to it, if the change be possible. Burdach placed porous vegetable substances, as wood and tinder, in the abdominal cavity, and found a deposit of fat on them, and which was imbibed in the pores, which speaks against the change in question. Finally, Burdach determined the fat of the egg of _Linnæus stagnalis_, and detected a considerable increase of it during the development of the embryo; but, on the other hand, the egg contains sugar from which the fat could have been formed; and in opposition to this the quantity of sugar in hens’ eggs has been noticed rather to increase than diminish during incubation. Quain & Virchow quoted by Lehmann,[4] examined muscle changed in macerating troughs to adipocire, and are of opinion that the fibrine is here changed to fat. I have questioned my medical friends, who have had experience in this matter, and find them to hold the same opinions. Prof. Leidy, who macerated with water the bodies of small animals, in stoppered bottles, to obtain their skeletons, found that the deposition of adipocire upon the bones was quite abundant.