r882.j Zoology. 325 



and man. The cattle plague of 1865 was at one time attributed 

 to this gregarine. 



Taking into consideration all these points, Professor Lankester 

 believes the bodies found by Gaule, and afterwards again observed 

 by himself, to be a stage in the life-cycle of a gregarine to which 

 he gives the name of Drepanidium ranarum. 



Professor Lankester disposes of Gaule's statement that these 

 bodies were formed on the stage of the microscope after the ap- 

 plication of the saline solution ; as well as of that observer's fail- 

 ure to discover them in living tissue, by showing that it is diffi- 

 cult to see the nucleus in living tissue, so much so that not 

 long ago it was thought that the red blood-corpuscle of the frog 

 contained no nucleus during life. The parasite is difficult to see 

 because its angle of refraction is the same as that of the corpuscle, 

 but it becomes visible///^/ at the same time and to the same degree 

 that the nucleus does. 



Dr. Gaule's studies, however, establish two facts not be- 

 fore known ; these are, 1st, that the parasite is not only found 

 attached to the cell, but also within it ; 2d, that it is capable of ac- 

 tive movement by bending and straightening its body; these 

 movements are excited by a heat of 30°-35° C, but are stopped 

 by a heat of yo° C. 



The active motions of these bodies, exhibited in cells as well 

 as in fluids ; the cessation of these movements at a temperature 

 of 70 ; the fact that they are found in some frogs and not in 

 others, as well as at some seasons and not in others; their power 

 to penetrate cells and escape from them ; and their presence 

 in R. temporaria, as well is Triton, sp., all point to their animal 



To Gaule's assertion that these bodies did not appear in fresh 

 tissue, Lankester opposes the statement that he obtained them 

 from spleen pulp spread when fresh in osmic acid, and suggests 

 the possibility that the particles treated in this manner by Dr. 

 Gaule were free from the parasite, while those treated otherwise 

 contained them. 



Vitality of the Mud Puppy. — The observations on the Meno- 

 poma in your February number, call to mind several instances of 

 its remarkable vitality which have come under my own observa- 

 tion. One specimen, about eighteen inches in length, which had 

 lain on the ground exposed to a summer sun for forty-eight 

 hours, was brought to the museum, and was left lying for a day 

 longer before it was placed in alcohol. The day following, desiring 

 to note a few points of structure, I removed it from the alcohol, 

 in which it had been compl teh Mibmcrged for at least twenty 

 hours, and had no sooner placed it on the table before it began to 

 open its big mouth, vigorously sway its tail to and fro, and give 

 other undoubted signs of vitality. 



On anotk / to kill one of these 



