BREEDING AND FAMILY LIFE 133 
been noted in a litter, while MacFarlane says seven and 
eight were not uncommon on Peace River, and an Indian 
told him of finding nine embryos in a female killed on lower 
Peace River. It should be mentioned that Hearne, who 
spent several years in the northwest fur country, found as 
many as six foetuses in a female in but two instances. Mor- 
gan mentions a trapper who found eight in a female caught 
by him, and who also found eight in a lodge. Earl Theron 
Engle says that two beavers taken in South Boulder Cajion, 
Colorado, February 23, 1924, each contained three embryos, 
7mm. and 9mm. in length. The government trapper who 
procured the animals said that the record is the earliest 
observed in several years trapping. 
One spring Mills visited several colonies to see if he could 
find out the number of children in a family. He saw one 
family of eight, and one mother had but a single baby. 
The average number was five. On May twelfth he saw 
six youngsters sunning themselves on top of a house. The 
fact that a beaver has but four teats might seem to indicate 
that four was the normal number of young. 
I have previously stated that there was an exception to 
the almost universal belief that beavers take but a single 
mate. Vernon Bailey makes the following statement: 
“Like all rodents, beavers are polygamous, and the fact that 
fights among the males take place indicates that the older 
ones strive for supremacy.”’ He also says that in August he 
found two females, one male, and six good-sized young in 
one house. As the sexes seem to be about equal in number 
polygamy appears rather doubtful to me. 
The male apparently leaves the home lodge or burrow 
about the time the young are to be born and takes up his 
abode in a burrow elsewhere. When the family are a 
few weeks old he returns to the lodge. Morgan states 
that at the age of six weeks the young will wean themselves 
