SUBCUTANEOUS INOCULATION OF ANIMALS 233 



process are practically the same in all cases. The hair or 

 feathers are to be carefully removed. If the skin is very 

 dirty, it may be scrubbed with soap and water. Sterili- 

 zation of the skin is practically impossible, so it need not be 

 attempted. If the inoculation is to be made by means of a 

 hypodermic syringe, then a fold of the skin may be lifted 

 up and the needle inserted in the usual way. If a solid 

 culture is to be inoculated, a fold of skin may be taken up 

 with forceps and a tiny pocket cut into it with scissors 

 which have previously been sterilized. This pocket must 

 be large enough to admit the end of the needle without its 

 touching the sides of the opening as it is inserted. Beneath 

 the skin will be found the superficial and deep connective- 

 tissue fascise. These must be taken up with sterilized 

 forceps, and with sterilized scissors incised in a way corre- 

 sponding to the opening in the skin. The pocket is then to 

 be held open with the forceps and the substance to be 

 inserted is introduced as far under the skin and fasciae as 

 possible, care being taken not to touch the edges of the 

 wound if it can be avoided. The edges of the wound may 

 then be simply pulled together and allowed to remain. No 

 stitching or efforts at closing it are necessary, though a drop 

 of collodion over the point of operation may serve to lessen 

 contamination. 



As the subcutaneous inoculation is very simple and takes 

 only a few moments, guinea-pigs, rabbits, and pigeons may 

 be held by an assistant. The front legs in the one hand 

 and the hind legs in the other, with the animal stretched 

 upon its back on a table, is the usual position for the opera- 

 tion when practised upon guinea-pigs and rabbits. The 

 point at which the inoculations are commonly made is in 

 the abdominal wall, either to the right or left of the median 



