72 ENTOMOLOGICAL NEWS. [Feb., '14 



4, H. placida 4. The best of these shows eight less than the 

 average and may be regarded as fragmentary. 



If a bee limits itself to a given flower, it gains the immediate 

 advantage of being able to anticipate other bees in their visits 

 to the chosen plant. It may increase this advantage by locating 

 its nests near the flowers. To humanize, it may concentrate its 

 attentions upon the flowers so as to get to them first, learn 

 how to manipulate the pollen better than other bees, and 

 finally develop special structures which will increase the ad- 

 vantage. 



I have pointed out that some oligotropes which collect large 

 pollen have loosely plumose scopae which are better adapted 

 to collect and hold the large grains, while some others which 

 collect the fine pollen of Compositae have densely plumose 

 scopae. 



Anthedon compta, an oligotrope of Oenothera, whose pollen 

 grains are hard to collect on account of being connected by 

 threads, has scopae of long simple bristles quite different from 

 its nearest relatives. After doing the best it can on the flower, 

 it goes to the stem and turns head downwards so as to work 

 the cobwebby pollen into its scopae. Other bees collect the 

 pollen, but Anthedon surpasses them all in the facility with 

 which it does so. 



The anthers of Verbena are included in a slender tube and 

 above them is a circle of hairs as if intended to prevent the 

 pollen from being extracted. Ordinary bees can only collect 

 the pollen which adheres to their proboscides. Verbcnapis 

 verbenae has its front tarsi provided with curled bristles. 

 When collecting pollen the bee thrusts both front legs into the 

 tube of the corolla and drags out the pollen with its front 

 tarsi. 



There are 223 indigenous nest-making bees. One species, 

 flying throughout the season and fitted about like Apis, except 

 for flowers of unusual construction, might collect nearly as 

 much pollen and support nearly as many individuals as all of 

 the 223 together. It would be to the advantage of this bee to 

 become as polytropic as possible, and, as the number of in- 

 dividuals increased, to extend its visits to the most difficult 



