390 C. H. TURNER 



in the same manner it did the first twig. If the added piece is 

 too long it is shortened by girdling. The food consists of powder 

 rasped from submerged wood. 



Noyes (93) has made a careful study of the net-spinning caddis- 

 worms of Caseadilla creek. She demonstrated, experimentally, 

 that they will construct tubes even in still water; but that nets 

 are only formed in the presence of a current. The different 

 species of Hydropsyche construct similar nets, and the net- 

 building behavior is as follows: — 1. They construct nets by either 

 day or night. 2. Two and a half to three hours is the average 

 time required to complete a tube. 3. No temporary construc- 

 tion threads are used. 4. There is no definite order in which the 

 threads are woven. 5. Particles are removed from the nets with 

 the mouth parts and not with the dorsal tufts of hairs on the 

 anal legs. 6. The front legs and the mandibles are used for 

 holding particles in position until they are fastened in place with 

 silk. 7. They are never too busy weaving to stop to capture 

 food that adheres to the net. She confirms Siltala's statement 

 that the food of these forms is both animal and vegetable. In 

 fall and winter diatoms form the bulk of the food; in spring and 

 summer minute animals predominate. At all times a moderate 

 amount of algae is consumed. 



ANTHOPHILY 



As a result of ten years devoted to their study in Maine and 

 Massachusetts, Lovell (78, 80) reports the discovery of 332 

 species of anthophilous beetles belonging to 127 genera and 29 

 families. This is 47 species more than Knuth records for all of 

 North America. He writes: " In all of the families, in most of 

 the genera and in very many of the species in which anthophily 

 occurs this habit has been acquired independently; but in the 

 case of Gnathium and Nemognatha it probably arose before the 

 genera were differentiated. Except in these two genera and to 

 a less extent in Chauglignathus and Lepturini the modifications 

 induced are obscure and indistinct; from which it may be in- 

 ferred that anthophily among the Coleoptera is of compara- 

 tively recent origin. The primitive Coleoptera lived largely 

 upon the ground and were carnivorous, but as they learned to 

 search for prey on plants and to feed upon vegetation anthophily 

 became correspondingly common. As pollinators of flowers the 



