and the seven or eight short stiff spines which spring from the floor of the corbicula immediately above its lower edge. As yet the pollen has not come in contact with the one long hair which rises from the floor and arches over the entrance. The planta is extended, thus lowering the auricle; b, represents a slightly later stage, showing the increase of pollen. The planta is flexed, raising the auricle. The hairs which extend outward and upward from the lateral edge of the auricle press upon the lower and outer surface of the small pollen mass, retaining it and guiding it upward into the basket; c, d, represent slightly later stages in the successive processes by which additional pollen enters the basket. (Original.)

If the collecting bee is watched for a few moments the increase will readily be noted and the fact will be established that the accumulating mass is gradually working upward or proximally from the lower or distal edge of the corbicula and is slowly covering the floor of this receptacle. (See fig. 8, b, c, and d.) In many instances the successive contributions remain for a time fairly separate, the whole mass being marked by furrows transverse to the long axis of the tibia.

Sladen (1912, b) notes the interesting fact that in those rather exceptional cases when a bee gathers pollen from more than one species of flowers the resulting mass within the corbicula will show a stratification parallel to the distal end, a condition which could result only from the method of loading here indicated.

As the pollen within the basket increases in amount it bulges outward, and projects downward below the lower edge of the basket. It is held in position by the long hairs which fringe the lateral sides of the basket, and its shape is largely determined by the form of these hairs and the direction in which they extend. When the basket is fully loaded the mass of pollen extends laterally on both sides of the tibia, but projects much farther on the posterior side, for on this side the bounding row of hairs extends outward, while on the anterior edge the hairs are more curved, folding upward and over the basket. As the mass increases in thickness by additions from below it is held in position by these long hairs which edge the basket. They are pushed outward and many of them become partly embedded in the pollen as it is pushed up from below. When the pollen grains are small and the whole mass is well moistened the marks made by some of the hairs will be seen on the sides of the load. (See fig. 9, a.) These scratches are also transverse in direction and they show that the mass has been increased by additions of pollen pushed up from below.

Even a superficial examination of a heavily laden basket shows the fallacy of the supposition that the long lateral fringing hairs are used to comb out the pollen from the brushes of either the hind or middle legs by the crossing of these legs over the lateral edges of the baskets. They are far from sufficiently stiff to serve this purpose, and their position with relation to the completed load shows conclusively that they could not be used in the final stages of the loading process, for the pollen mass has completely covered many of them and its outer surface extends far beyond their ends. They serve merely to hold the pollen in place and to allow the load to project beyond the margins of the tibia.

The auricle plays a very essential part in the process of loading the basket. This structure comprises the whole of the flattened proximal surface of the planta, except the joint of articulation itself, and it extends outward in a posterior direction a little