158 Miscellaneous, 



tion of the membranous intervals, and presenting, with the exception 

 of the mouth and nostrils, no other orifice than the anus ; for it is 

 well known that the hemispherical membrane which protects exte- 

 riorly the globe of the eye is part of the integuments, and comes oif 

 along with the rejected skin. This skin, at first soft, soon dries, 

 and is easily preserved in cabinets ; but it is rare to find it entire, 

 because it is often torn in the operation we have described. We 

 possess some specimens of several foreign species which prove that 

 the moulting is produced in the same manner in all serpents. — From 

 Dr. Schlegel's Essay on the Physiognomy of Serpents, translated by 

 Dr. Traill. 



ON A NEW SPECIES OF HiEMATOZOON, TRYPANOSOMA SANGUINIS. 

 BY M. GRUBY. 



This new species of parasite, which is extremely remarkable from its 

 form and its motions, occurs in the blood of living adult frogs during 

 the spring and summer months. Its elongated and flattened body 

 is transparent, and in shape resembling an auger ; its cephalic por- 

 tion terminates in long minute filaments ; its caudal portion also ter- 

 minates in pointed filaments. The length of the animal is from forty 

 to eighty thousandths of a millimetre, its breadth from five to ten : 

 the cephalic filamentary portion is endowed with the greatest mobi- 

 lity ; the length of the cephalic filaments is from ten to twelve 

 thousandths of a millimetre ; its body is elongated, flattened and 

 dentated like the blade of a saw the whole length of one of its mar- 

 gins ; it is smooth, and turned continuously twice or thrice round its 

 axis like a gimblet or corkscrew, for which reason I propose to call 

 this Hsematozoon Trypanosoma. 



The locomotion of the Trypanosoma is very remarkable ; the rapi- ' 

 dity with which it moves every part to produce the motion around 

 its longitudinal axis, i. e. the boring movement, and then the address 

 which it shows in avoiding every obstacle it meets in its course, is 

 admirable : we may count four revolutions around its axis in a second, 

 or 14,400 in an hour. 



When this animal is still, it contracts so as to form a compact and 

 smooth cjdinder, one end of which is rounded, while the other ter- 

 minates in a brush. At first sight it appears to be quite a different 

 animal, so much is its form changed ; but on observing it when it is 

 in the act of contracting itself, it is seen to place itself so that the 

 smooth margin of its body shall form the surface and the rounded 

 end of the cylinder, while the appendages are partly inclosed and 

 pressed in the interior of the cylinder, and moreover form with their 

 elongated points the other extremity, which has the appearance of a 

 brush. 



The Trypanosomata of the blood are not so common as the Filarice ; 

 they occur in two or three out of a hundred frogs, and in each drop 

 of blood will be found two or three Trypanosomata. They are some- 

 times met with in the blood of frogs along with Filarice, but these 

 latter are always more numerous. Young frogs have no IVypanoson 



