476 DISEASE IN WILD MAMMALS AND BIRDS 
trated deeply into the muscle, but extension had taken 
place only to a single submaxillary gland. A squamous 
epithelioma was found on the skin of the thigh of a Tas- 
manian de\dl (SarcopJiilus iir sinus). The construction 
was somewhat unusual in that it w^as cystic but lined with 
squamous and keratinized plates. It could not be decided 
that it originated from glands like a trichoepithelioma; 
it was not like a basal cell cancer. No metastases had 
occurred. The third case was that of a tumor within the 
abdomen of an Amazon {Chrysotis leucocephala) . It con- 
sisted of an illy defined basement membrane upon which 
were irregular stratified squamous epithelial cells. Upon 
the surface w^ere wavy bands of horny material, very 
much like dried and cast-off epithelial scales, except 
more compact and extensive. These latter seemed to 
form the bulk of the mass. Beneath the membrane a few 
irregular accumulations of cells bearing a similarity to 
those on the surface could be found, but they were prob- 
ably large plasma cells. The epithelial layer dipped down 
like in epithelioma. No pearls or separate nests were 
found. While this mass was not localized, it was doubt- 
less an epithelioma, and should be included in this 
series. Its possible origin in the small intestine has 
been considered. 
The question of the occurrence of tumors in wild 
animals seems fairly well settled when twenty-five 
examples of malignant epithelial neoplasms can be dis- 
covered in fifty-three hundred autopsies. It is interesting 
to note the incidence of these tumors in wild- and park- 
bred animals. Exclusive of the parrakeets there are 
twenty-one cancers, seventeen in known wild-bred, two in 
known park-bred specimens, and two wdth breeding un- 
certain. The average known duration of captivity of the 
wild-bred animals is about four years, while the two park- 
bred animals lived eight and eighteen years. Thirteen of 
the twenty-one cases were males, eight females. Adeno- 
carcinoma was discovered twelve times, simplex nine 
