64 Annals Entomological Society of America [Vol. Ill, 



was thou^'ht desirable to permit the flea greater latitude making 

 the trial fairer and more practical. Twenty fleas (eight males 

 and twelve females) were placed in a rectangular porcelain dish, 

 the dimensions of which were 1 1 7-8 inches by 7 5-8 inches Ijy 

 2} inches deep. A light sprinkling of moist sand was placed in 

 the bottom of the dish to provide a firm footing and the sides of 

 the dish were extended to the height of 4.^ inches, enclosing the 

 container entire! \- by strips of "tangle-foot" paper. At the end 

 of twenty-four hours the dish with the fleas was examined, and it 

 was obser\-ed that several fleas had leaped high enough to 

 l)ecome entangled on the adhesive paper. The position of these 

 Avas noted, the distance from the bottom of the pan was meas- 

 ured. The entangled insects were pried off, the sticky material 

 •dissolved with alcohol and the insects examined microscopically. 

 P"'ive specimens were collected, two males and three females. 

 The locations on the adhesive paper relative to the l)ase of the 

 dish were as follows: 



1 F. 2J inches 1 F. A 1-8 inches 1 F. 2 9-16 inches 



I 1 .M. 2 5-8 inches 1 M .i 1-1(1 inches 



A census of the fleas remaining in the bottom of the dish ga\-e 

 C M. and q F. showing that none jum])cd over the surrounding 

 paper, and that all jum])ing over 2. 1 inches were embedded in 

 the adhesive paper. 



The jumping powers of f\ irritans were further tested, twenty 

 fleas of this s])ecies being i)laced in a rectangular museum jar, 

 the inside dimensions of which were 2\ x 5. J x 7f inches depth. 

 The glass lid of the jar was coated with "tangle-foot" and the 

 sides of the jar within two inches of the top were likewise coated, 

 with the same material. The following morning the jar was 

 examined and two s])ecimens were seen embedded in the ' ' tangle- 

 foot" on the lid. The inside height of the jar being 7! inches 

 from the base gi\-es then this height as the perjx^ndicular jump. 



Concerning the fleas ability to walk upwards on glass, we ha\e 

 noted that they cannot climb to any considcralile distance. A 

 great number of counts were made, the greatest distance obserxed 

 being | inches. The climb appears very laborious and in all 

 cases the flea dropped to the bottom of the jar after a few eft'orts. 



We have observed the manner in w liich these insects can find 

 their way about upon their natural hosts. They pilot their paths 

 among the dense hairs, walking on the flat of their tarsi, seeming 

 to shuflle along. When on the animal they seldom hop al)Out, 



