Extensive autumn rambles in the mountains with especial attention to beaver customs compels me to conclude that as a basis for weather prediction beaverdom is not reliable. In the course of one autumn month in the mountains of Colorado more than one hundred colonies were observed. In many colonies work for the winter commenced early. In others, only a few miles distant, preparations for the winter did not begin until late. In some, extensive preparations were made for the winter. In a few the harvest laid up was exceedingly small. Thus in one month of the same year I saw some beaver colonies preparing for a long winter and others for a short one, many preparing for a hard winter and others almost unprepared for winter. From these varied and conflicting prognostications, how was one accurately to forecast the coming winter? The old prophets in one colony frequently disagreed with aged prophets who were similarly situated, but in a neighboring colony. At one place thirty or more beaver gathered an enormous quantity of food, sufficient, in fact, to have supplied twice that number for the longest and most severe winter. The winter which followed was as mild a one as had passed over the Rocky Mountains in fifty years. Not one tenth of the big food-pile was eaten. I have not detected anything that indicates that the beaver ever plan for an especially hard winter. Goodly preparations are annually made for winter. Apparently the extent of the preparation in any colony is dependent almost entirely upon the number of beaver that are to winter in that colony. Winter preparations consist of gathering the food-harvest, repairing and sometimes raising the dam, and commonly covering the house with a layer of mud. Beaver display forethought, intelligence, and even wisdom, but being weather-wise is not one of their successful specialties. Local beaver now and then show unusual activity, and unusually large supplies are gathered and stored for the winter. This kind of work appears to be local, not general. The cases in which unusually large preparations were made for the winter could have been traced to an increased population of the colony that showed these activities. On the other hand, colonies with less preparations one year than on the preceding one probably had suffered a decrease of population. Increase of population in a beaver colony may be accounted for through the growing up of youngsters, or by the arrival of immigrants, or both; where the temporary inactivity of trappers in one locality might allow the beaver colony in that region to increase in numbers; or where the beaver population of that colony might be increased by the arrival of beaver driven from their homes by aggressive hunters and trappers in adjoining localities. At any rate, in the beaver world, some colonies each year commence work earlier than do others, and some colonies make extensive preparations for the winter, while others make but little preparation. This preparation