HARRIS AND KUCHS : OBSERVATIONS ON l'OLLINATION. 29 



potatoes. In these, while large and plump, there is almost no 

 pollen-bearing Layer, and usually no apical pore opens for the 

 discharge of pollen." 



In < '. marilandica, as Meehan has shown, autogamy is impossi- 

 ble, while in S. rostratum autogamy may possibly sometimes 

 take place. 



The bee visits the llower for pollen ; contrary, however, to 

 the statement of Professor Todd, that "the flowers have neither 

 nectar nor odor," the writers observed that, especially in the 

 early morning, the odor was decidedly pronounced. It was ob- 

 served that the bee collected no pollen from the large stamen, 

 but took it regularly from the four smaller. This it did by 

 grasping the anthers, one at a time, near the base, and forcing 

 the pollen out through the terminal pores, by pinching it through- 

 out the length between its mandibles. An exception to this in 

 the case of Agopostemon texanus Cress, is already noted in the 

 list of species. It will be remarked that our observations on 

 this point correspond in general to those of Professor Todd. 



Of course the statement of Professor Todd, that the next 

 llower of the opposite type which is visited by the bee is very 

 apt to be on another plant, loses entirely its significance, since 

 it has been shown that the flowers on a branch are not at all 

 likely to be all right- or left-handed. In visiting the flowers, 

 the bumblebees, as a general rule, simply pass to the flower 

 most conveniently at hand, and this flower is very apt to be on 

 the same plant, especially where the plants are at all large. 

 The humblebees especially work vigorously in the early morn- 

 ing. In a patch of S. rostratum examined between eight and 

 nine o'clock, in St. Joseph, Mo., nearly all the flowers had 

 already been visited. At this time fifteen specimens of humble- 

 bees were taken. A great many flowers would be visited by 

 the bee before it found one which had not already been de- 

 spoiled of its pollen. In visiting such flowers, the bee would 

 alight for a moment on the pistil and large stamens, as de- 

 scribed above, and then pass on to the next flower when it had 

 ascertained that there was no pollen present. In this way over 

 twenty flowers may be visited in a minute. It will be seen that, 

 when the bees are at all numerous and as well dusted with 

 pollen as they usually are, the pistil is almost certain to re- 



