Royal Physical Society. 185 



easy and harmless does this act of the animal appear, that it 

 may almost be classed among the functions. 



6. Reproduction of Parts. — No sooner is the animal sub- 

 jected to mutilation than the reparative, and, to a certain 

 extent, reproductive, process is instituted. If the loss has 

 been the result of the instinctive efforts of the animal, the 

 parts seem very rugged and irregular, though, on examination, 

 a sort of three-fold dislocation is found to have taken place — 

 scale from scale, muscle from muscle, vertebra from vertebra. 

 As in other animals in similar circumstances, lymph is thrown 

 out. which at first covers the stump, and from day to day is 

 added to, till there is a prolongation of a conical form to the 

 extent of about half-an-inch, the reproduced part varying in 

 length and form in almost every case — a result depending, 

 apparently, on the stage of growth at which the animal has 

 arrived. This new structure is at first covered by an imper- 

 fect envelope, which comes off with the slough ; but in the 

 course of time (from four to six months) scales are formed, 

 and the reproductive process is at an end. In the case of an 

 aged animal, the reproduced part, at 3 inches below the 

 cloaca, is 5 lines ; and in a younger specimen, at 2 inches 

 below the cloaca, the reproduced part is 7 lines in length — 

 the first being composed of seven rows of scales, and the 

 other often rows, including, in both cases, the terminal conical 

 scale. The scale-plates and scales of the reproduced part are 

 comparatively strong, small, and numerous. In the first case, 

 the part was separated where the scales are ten in number in 

 the circumference of the tail ; the new scales, at the point of 

 union with the old, are twenty in number. In the other 

 case, the scales at the severed part are twelve ; those of the 

 reproduced portion, at the point of union, amount to eighteen. 

 Vertebrae are not reproduced. 



7. Gestation and Hybernation. — The periods of hyberna- 

 tion and of gestation of the Anguis fragilis I have never 

 been able to determine by the closest observation. The ar- 

 tificial method of keeping reptiles, necessarily adopted by the 

 naturalist for acquiring a minute knowledge of their habits, 

 is not the best for all purposes. The more equal temperature 



