1886. MAMMALS IN THE SOCIETY'S GARDENS. 215 
atlas had become firmly ankylosed to the occiput, and it is very 
curious that the animal could have survived so serious an accident. 
A somewhat similar case came under observation in an Ichneu- 
mon. In this instance the atlas had been dislocated from its rela- 
tions to the occiput and axis, so as to occupy the situation shown in 
the accompanying drawing (fig. 7). In this instance the animal 
must have survived the injury a long time, because the occiput and 
atlas are firmly united by new bone. 
Concretions formed of insoluble or indigestible matters are of 
frequent occurrence in the alimentary canal of Horses and Cattle, and 
at times may attain to very large size without causing any incon- 
venience. ‘This is more particularly the case when these zgropiles, 
as they are termed, occur in the ceecum of horses. In this situation 
they have been known to weigh more than fifty pounds. These 
heavier masses are composed of magnesium phosphates ; the lighter 
ones consist of hair which the animal licks from its body. This 
forin is fairly frequent in calves, and I have met with a specimen in 
a Hyena. Concretions of insoluble substances, such as magnesia, 
pins, seeds, &c., occur also in the human subject. Recently a Tiger 
died in the Gardens, and its bowels were found empty until the 
rectum was reached. Here a large mass of solid material was found 
about two inches from the anus, measuring six inches in length and 
eight inches in girth, covered with mucus. The lower end was 
bluntly pointed, and had caused by its pressure ulceration of the 
mucous membrane. The rectum was much dilated. On breaking 
into the mass it was found to be composed entirely of sawdust, 
which the animal had licked from the floor of the eage. A cast of the 
abnormal mass was taken at the time by the assistant, Mr. Ockenden. 
During the past four or five years there is one fact more than any 
other which has impressed me in the course of my work at the 
Gardens, and that is the infrequency of neoplasms. In the many 
hundreds of animals coming under observation, a tumour has been 
a rarity, and this applies with still greater force to cancers. The 
only example of this terrible malady I have seen in wild animals 
was a medullary cancer in the viscera of a Python. ‘The infrequency 
of these growths makes the following case additionally interesting. 
A Short-headed Phalanger, Belideus breviceps, was found to have 
a large, hard nodular mass in its marsupium. On slitting open the 
pouch a tumour presented itself, having the appearance represented in 
fig. 8, p. 216. Microscopically it presented all the characters peculiar 
to scirrhous cancer as seen in the human subject—that is, there were 
alveolar spaces enclosing masses of cells. ‘The alveolar walls were 
composed of dense fibrous tissue. The structural details of the 
growth coincided with that of the gland from which it originated, 
except that the cells, instead of clothing the walls of the alveoli in a 
regular manner, were tumbled in confusion into the interior. This 
case is, so far as I know, the first authentic example of cancer in a 
marsupial. 
The last specimen on my list is perhaps as interesting as any. It 
is an intussusception of the ileum into the cecum, through, but not 
