THE COMMUNICABLE DISEASES 489 
chronicity — then following in order the massive caseous 
form including caseous pneumonia, the caseous miliary or 
nodular form so well represented by the monkey, then the 
fibroulcerative type such as one encounters in human 
consumption, including also forms in which fibrosis pre- 
dominates, and lastly the rather uncommon pearl disease. 
This classification has been relatively easy to follow and 
can be readily imagined by the reader. There are of 
course intermediate cases or transition forms and there 
have been instances partaking of more than one character. 
The groupings present only gross appearances and, with 
few exceptions, are not to be taken as direct indications 
of type incidence in special groups. 
Visceral distribution is shown in the last gross section 
of the table; single cases or unusual locations are not 
tabulated but will be separately discussed. The visceral 
distribution is made upon evident gross lesions or their 
discovery in organs whose condition suggested the need of 
microscopic study for confirmation. The figures in the 
table will be reviewed first upon the incidence as a whole 
and then between classes and orders. This will be suc- 
ceeded by an analysis of the particulars for each order 
and then for each of the pathological headings. 
Total and Class iNcmENCE. 
The autopsies upon 5,365 animals have revealed the 
existence of tuberculosis in 492, a percentage of 9.1. This 
means that lesions due to the Bacillus tuberculosis were 
present, but they were not always the cause of death, since 
many specimens have been executed and others have had 
sufficient pathology to kill, aside from the tuberculous 
changes. Deaths due to the disease alone are difficult to 
estimate, but seem to be about 325 or 6 per cent. These 
figures, while they represent the total incidence, lose con- 
siderably in significance when the factors are analyzed. 
Mammalian incidence is 14.7 per cent.. Avian 6.2 per cent., 
but the former is based upon figures obtained from six of 
32 
