162 THE HANDLING OF ANIMALS 



hooks, then pass it between the ears, and fasten the end to the other hook. The 

 apparatus is fixed on to the tray by means of a screw clamp. The animal can be 

 secured to the tray and its head held by the ring, either on its back or belly at wilL 



Anaesthetics. Rabbits are very sensitive to anaesthetics. Chloroform 

 should not be given either slowly or in small and repeated doses, because it 

 will thus almost certainly kill the animal ; but by giving a large dose to 

 begin with and then stopping the administration after a few moments 

 accidents can almost always be avoided. 



Twist two or three thicknesses of filter paper into a cone, pour a teaspoonful 

 of chloroform on to it and hold it over the animal's mouth. Respiration 

 stops after a few seconds but soon begins again ; at this moment anaesthesia 

 is complete ; the administration of chloroform should now be stopped, and 

 the Operation quickly performed. 



2. Guinea-pigs. 



It is best to catch guinea-pigs by the skin of the back ; they are easier to 

 handle than rabbits, and can generally be held in the left hand, leaving the 

 right hand free for inoculation. 



If it be desired to hold a guinea-pig with instruments the simplest way is 

 to catch hold of the animal by the skin of its back with a large pair of 

 pressure forceps, the grasping ends of which are ring-shaped (fig. 131). The 



FIG. 131. Forceps for grasping small animals. 



forceps being clipped together are hung by one of the finger holes on a nail in 

 the wall, and the animal being thus suspended is rendered quite motionless. 



For holding guinea-pigs still while taking temperatures, making inocula- 

 tions into the hind limbs, etc., it will be found convenient to secure the 

 anterior part of the animal in a metal cylinder with slits along the sides. 



For carrying out delicate operations, it is preferable to fix the animal on 

 the tray described above. Such trays should be kept in two sizes, the larger 

 ones for rabbits and the smaller for guinea-pigs. 



Anaesthetics. Guinea-pigs are less susceptible to chloroform than rabbits. 

 It is very seldom that they have to be anaesthetized, but should it be necessary 

 to give a guinea-pig an anaesthetic, the method of administration is the same 

 as for rabbits. 



3. White mice and white rats. 



To catch the animals. These species are perhaps in a general way more 

 used for experimental inoculation than any other " laboratory animal." 

 They can be caught by the tail with the fingers. Sometimes they struggle 

 and may inflict a painful bite ; this can be avoided by grasping them by the 

 tail or skin of the neck with a pair of forceps. 



To hold them for inoculation, the only method that can be recommended 

 is to catch hold of the tail with the fingers or a pair of forceps and draw it 

 out of the pot, the animal being thus suspended head downwards inside ; 

 then, as a precaution against being bitten put a small piece of board over the 



