When Caribou flee from some source of alarm, a distinct tendency toward compact bunching may be observed. This may have been developed as a measure of protection from pursuing Wolves; the latter could naturally overcome a straggling or isolated individual more readily than one in a compact herd. The Caribou running away from the train in the “Little Barrens” south of Churchill very clearly demonstrated the tendency toward a close formation. (See also, in the section on _Disposition_, the account of a herd attacked by a hunter near Lake Charles.) The larger herds of the autumn migration seemed to be generally composed of all sexes and ages; yet some sizable bands were made up chiefly of bucks on the one hand, or of does and fawns on the other hand. The rear guard of the spring migration and the vanguard of the autumn migration are generally composed of bucks, traveling either singly or in small bands; this state of affairs is looked upon as evidence that the majority of the bucks do not advance so far to the north in June and July as the does do. The following are a few examples of the composition and leadership (or rear-guarding) of groups of Caribou. (Other examples are mentioned in the sections on _Migration_.) A band of about 20, after feeding for a time on the south bank of Windy River on June 16, moved off upstream, mostly in single file, with a patriarchal buck in the lead. The remainder of the band included several lesser bucks and various does and yearlings. On the following day a band of equal size, composed chiefly of bucks but including three hornless individuals (does?), was led by two of the bigger bucks. When a band of some 40 does and fawns approached Little River to cross it on August 25, a doe came first to the water’s edge to make a careful inspection. On the same day I remarked having noted several times that a buck brought up the rear of a band. On August 26 I noted that a distinct majority in the herds of the previous two or three days were does and fawns, although there were generally a few bucks present also. At this period I got the impression that the number of individuals in a band was frequently not far from 25. On August 28, when a band of 40 crossed the mouth of Little River, three or four bucks plunged in first, but a doe was almost even with them. At the Bear Slough, on September 3, a group consisted of two bucks, two does, and a fawn. On September 15 Fred Schweder, Jr., reported seeing about 100 Caribou, with not a buck among them. On September 24 about 15 does and fawns were resting or feeding quietly by Glacier Pond. On September 28 a band of six large bucks crossed the Camp Ridge. On October 1, an older and a younger buck appeared in the shoal waters of Duck Bay. On November 3, in the same locality, a band of about 50 was composed largely of does, but included a few fawns and a few well-antlered bucks. On November 11 five does were reported crossing the mouth of Windy River on the ice.