132 



little change. On microscopic examination we find that the alveoli 

 are eitlier filled with larger or smaller numbers of bacilli or with 

 a cellular exudate consisting of leucocytes, alveolar epithelia, and 

 erythrocytes, mixed with smaller or larger numbers of plague 

 bacilli. The interalveolar septa are generally widened by an (ede- 

 matous infiltration and by a swelling of the cells and fibers. The 

 capillaries are greatly dilated and engorged; they may be free 

 from plague bacilli or may contain metastatic emboli in complicated 

 cases. Fibrin may be either present or absent. 



THE SPLEEN. 



Much emphasis has been laid upon the enlargement of the spleen 

 in plague. Some observers have even gone so far as to state that 

 this organ is always markedly enlarged in this disease and not 

 infrequentl}^ very much increased in bulk. However, we have, 

 among our i^ost-mortem material four cases (Nos. 4, 5, 10, and 17) 

 in which the spleen was not enlarged and two (^o. 14, Filipinos 

 sixty-three years old, and Ifo. 18, Chinese twenty-seven years old) 

 in which it was very small. On the other hand, most cases of 

 plague show a considerable increase in the size of this organ, which 

 then is generally about two to three times the bulk and weight of 

 the normal one (Cases A^os. 1, 2, 7, 9, 12, 13, 15, 16, 19, and 20). 

 In three cases (Nos. 3, 6, and 8) a very considerable enlargement 

 was found, in one of which at least an increase of the organ to 20 by 

 12 by 7 centimeters and a weight of 865 grams, was clearly due to 

 causes existing prior to the plagxie infection. One must not forget 

 that splenomegaly is a very common finding in the Tropics; and 

 hence if a very large spleen is encountered in a plague case the 

 possibility of this being due to some other cause must always be kept 

 in mind. We have taken great pains to search for the Donovan- 

 Leishman bodies in those of our plague and in other post-mortem 

 cases which showed extensive enlargement of the spleen, but we 

 have never encountered them. This demonstrates, to a certain 

 extent at least, that all cases of tropical splenomegaly can not be 

 attributed to the Donovan-Leishman infection. In plague the 

 enlarged spleen is generally, though not always, soft in consistency, 

 dark purplish-blue externall}^, and dark brownish-red on the cut 

 surface. On section the pulp generally protrudes and a large 

 quantity of juice can iisually be scraped off. The trabeculse as a 

 rule are distinct, but the follicles are commonlv not very clear. 



