Miscellaneous. 463 



the supposition of a de novo origiuation of living units, so long as 

 those which may have preexisted in the flasks could be proved 

 to have been reduced to such a state of potential death. It would 

 be preposterous, and contrary to the whole order of Xature, to 

 assume that the vastly increased destructive influence of a heat of 

 212° P. had restored vital properties which a lesser amount (158° 

 F.) of the same influence had completely annulled. 



The evidence supplied by these different series of experiments, 

 in whichever way it is regarded, as it seems to me, absolutely 

 compels the logical reasoner to conclude that the swanns of living 

 organisms wliich so often make their appearance in boiled infusions 

 treated in one or other of the various modes already proved to be 

 either destructive or exclusive of preexisting living things are the 

 products of a new brood of " living " particles, which, in the absence 

 of any coexisting living organisms, must have taken origin in the 

 fluid itself. For this mode of origin of living units, so long 

 spoken of and repudiated as " spontaneous generation," I have 

 proposed the new term Archebiosis. 



MISCELLANEOUS. 



Habits o/Xenurus unicinctus, or Cahassou. 

 By Dr. J. E. Gray, F.R.S., F.Z.S., &c. 



A SPECIMEN of this animal has been living in the Zoological 

 Gardens for this last three or four months. 



It feeds freely on chopped meat and vegetables. 



The head is very blunt, with a broad, truncated, flesh-coloured 

 nose with large nostrils. The ears are very large and covered with 

 scales ; they are usually open and spread out, but always have a 

 keel on the inner side ; the fore and hinder flat surfaces are fre- 

 quently completely closed by compressing the two sides of the car 

 very closely together, perhaps to protect the cavity of the ear from 

 the sand of the places they are said to inhabit. The body is broad, 

 depressed, and sunk in the middle of the back, and the dorsal disk is 

 very soft and flexible. The tail is elongate, subcylindrical, blackish, 

 naked, and smooth, with three longitudinal series of calcareous 

 tubercles on each side of the imder part of the hinder half of the 

 tail, which are of a roundish shape and are sunken into its sub- 

 stance so as to bo level with the surface. The front claws are very 

 large, and squarely truncated at the end, from the animal's habit 

 of walking on the tips of them. The frout fingers are very mobile ; 

 and the animal is constantly spreading them out, so that they 

 radiate from one another and can make a very broad foot, if re- 

 quired by the place it inhabits. The hind claws are similar, but not 

 quite so large or unequal. The penis is long, fusiform, and entirely 

 retractile. The front claws of the wild specimens in the Museum 

 are not.so much truncated as those of the specimen in the Zoological 

 Gardens ; and though the tubercles on the tail are present in the 



