416 C. H. TURNER 



the insect remains a potential transmitter for a very long period. 

 Anothei class are the trypanosomes which apparently thrive 

 in a number of different vertebrate hosts and may be trans- 

 mitted from cattle or wild beasts to man. But the observations 

 on this point are by no means conclusive and it is quite possible, 

 as has been repeatedly suggested, that a number of organisms, 

 different but indistinguishable, are involved. It may prove that 

 revision of data, from the present viewpoint, may materially 

 alter our conceptions on the subject." 



PARASITISM 



Knab (48) reports a fly that is parasitic on man. 



Girault (34) recoids some simple experiments which he per- 

 formed with the human body louse. 



Matheson and Crosby (58) discuss the habits of three hymen- 

 op terous egg parasites. 



Ewing (27) gives a classification of parasites that covers two 

 octavo pages. In the Acarina he finds evidence that parasitism 

 has arisen in the following three ways: (1) by predaceous 

 forms beginning to prey upon foims that are larger than they; 



(2) by scavengers passing from feeding on dead bits of animal 

 and of plant tissues to feeding on the same tissues attached to 

 a living oiganism and thence to feeding on the living organism; 



(3) by forms originally adapted for sucking the juices of plants, 

 transferring their operations to animals. He gives a list of 

 parasites and their hosts, and, in tabulated form, he records 

 the duration of life of many mites after being removed from 

 the body of their host. 



LOCOMOTION 



Bervoets (3) has published a short article on the flight of 

 insects, and Collinge (19), a short note on the locomotion of 

 the young of Pulvinaria vitis var. ribesiae. 



H. W. B. Moore (63) describes the locomotion of a large 

 number of caterpillars. 



Matheson and Crosby (58) describe the behavior of three dif- 

 ferent species of American hymenoptera which swim, submerged 

 in water, by means of their wings. These species are: Hydro- 

 phylax aquivolans M. and C, Limnodytes gerriphagus Marchal 

 and Caraphractus cinctus Walker. 



