54 Frerp Museum or Natura History — Zodxocy, Vot. XI. 
island in Rock River near Oregon, Ogle County, northwestern Illinois. 
It has also been taken in the vicinity of Glen Ellyn, Du Page County, 
Illinois, by Mr. B. T. Gault, who writes, ‘An Opossum was found 
dead in our woods February 19, 1910, evidently having been killed 
by dogs. It was quite badly mutilated and the fur slipped consid- 
erably, probably having been dead some time. Another one was 
killed here New Year's day and the man who did it tells me he has 
taken two others within the past ten years.’ I have seen a specimen 
killed near the Kankakee River not far from the Indiana line, and 
another from the vicinity of Warsaw, Hancock County, Illinois. It is 
also recorded by Dr. J. A. Allen from the latter locality (J. ¢., p. 162). 
Farther south it becomes more common and is reported from various 
places in southern Illinois. The Field Museum collection contains 
specimens taken near Bogota, Jasper County, and Olive Branch, 
Alexander County. 
The Opossum is very prolific; usually two and sometimes three 
litters are born in a season and the young usually number from 8 to 13 
ina litter. When born they are extremely small, considerably less than 
an inch in length, imperfectly developed, naked and absolutely helpless. 
They are immediately placed in the pouch by the mother, where they 
attach themselves to 
the nipples and remain 
so for several weeks 
until sufficiently grown 
to be able to move 
about and help them- 
selves. When they are 
able to leave the 
pouch, they are often 
carried about on the 
back of the old Opos- 
sum, clinging to her fur 
and with their tails 
wrapped around that 
of their mother, which 
she obligingly holds 
over her back for the 
purpose. 
Opossums are noc- 
turnal in their habits, 
although I have occasionally met with one wandering about in the 
woods in the day time. They move slowly when on the ground and 
