238 



BACTERIOLOGY. 



larger animals the form of holder shown in Fig. 42 is 

 commonly used. 



The holder devised by Sweet, 1 which can be made of 

 any size, from that suitable to a guinea-pig up to that 

 large enough to secure a dog, is in every way the most 

 convenient that we have encountered and, from the 

 standpoint of the animal, is the most humane. It con- 



FiG. 43. 



sists of four pieces of heavy round wire so bent that two 

 engage the animal immediately behind the lower jaw 

 while the remaining two close over the muzzle. All 

 are held in position by a single clamp controlled by a 

 single thumb-screw. When the screw is reversed and 



1 Sweet: " A simple, humane holder for small animals under exper- 

 iment," University of Penna. Med. Bull., 1903, No. 2, p. 78. 



