218 Experimentation upon Animals 



anesthetized and a formal laparotomy done, the wound being 

 carefully stitched together. 



When, in studying Pfeiffer's phenomenon and similar con- 

 ditions, it is desirable occasionally to withdraw drops of 

 fluid from the abdominal cavity, a small opening can be 

 burned through with a blunt needle. This does not heal 

 readily, and through it, from time to time, a capillary pipet 

 can be introduced and the fluid withdrawn. 



Small animals, such as rabbits and guinea-pigs, can be 

 held in the hand, as a rule. Guinea-pig and rabbit-holders 

 of various forms can be obtained from dealers in laboratory 



Fig. 61. Latapie's animal holder for rabbits, guinea-pigs, and other 

 small animals. This form of holder is in general use at the Institute 

 Pasteur in Paris. 



Fig. 62. Guinea-pig confined in the holder. 



supplies. The best of these is undoubtedly that of Latapie, 

 shown in the accompanying illustration (Fig. 61). Dogs, 

 cats, sheep, and goats can be tied and held in troughs. A 

 convenient form of mouse-holder, invented by Kitasato, is 

 shown in figure 63. 



In all these experiments one must remember that the 

 amount of material introduced into the animal must be in 

 proportion to its size, and that injection experiments upon 

 mice are usually so crude and destructive as to warrant the 

 comparison drawn by Frankel, that the injection of a few 



