466 Observations on Inoculation xcitk the Vims of 



section through the centre of the inoculated part presented the 

 appearance which is shown at Fig. A, Plate III. Congestion of 

 the vessels, with exudation of serous fluid into the areolar tissue 

 of the part, give a somewhat peculiar aspect to the cut surface, 

 and it can be understood how a fervid imagination would recog- 

 nise some resemblance to the marbled appearance of the cut 

 surface of a diseased lung ; it may be doubted, however, if any- 

 thing is to be gained by the comparison. 



Amputation of the swollen part of the tail is sometimes suc- 

 cessful in preventing the upward progress of the inflammation ; 

 but occasionally, in spite of every precaution, the swelling ex- 

 tends up the whole length of the tail to the hind quarters ; much 

 suffering is occasioned, accompanied with sympathetic fever, and 

 it becomes necessary to amputate the tail close to its origin. 

 This operation does not, in such severe cases, always succeed in 

 saving the animal's life. Fatal blood poisoning is, however, so 

 extremely rare as a result of inoculation, when proper care is 

 taken, that it need not form an important element in the dis- 

 cussion. 



When the first amputation is effective in staying the course of 

 the disease, the exudation of serous fluid from the surface of the 

 wound is often considerable ; and when the part is perfectly 

 healed a mass of dense fibrous structure is left, covered with scaly 

 cuticle, producing the appearance which is depicted in Plate IV, 



The fluid which exudes from the swollen tail has all the 

 characters of the exudate from the diseased lung. The germinal 

 matter is quite as abundant as in the fluid from the chest in 

 the advanced stage of the disease (see Fig. 2), as the next illus- 

 tration (Fig. 4) will indicate. 



The description which has been given of the local effects of 

 inoculation may be accepted as the expression of the sum of the 

 results which are obtained. Variations are observed in the 

 intensity of the action, and in the periods which are occupied in 

 the development of the phases of the local disease, but the 

 ordinary and characteristic effects may be thus described : — For 

 about ten days after the operation no morbid action is appa- 

 rent : this period may, therefore, be taken to represent the time 

 of incubation. Then exudation commences, and continues for 

 several days j this period may represent the development of the 

 local disease. Then the swelling gradually subsides, and, by the 

 end of a month after inoculation, a narrow dry scab only remains : 

 this period may represent the natural cure of the affection. 



It must be allowed that the only remarkable thing in the whole 

 process is the fact of the virus remaining dormant in the inocu- 

 lated part for several days. A similar swelling, the result of 

 exudation, may be induced by the aid of any irritating material, 



