RECREATIONS WITH THE MICROSCOPE 



151 



a pair of grappling hooks on the end of 

 a jointed arm which is normally fold- 

 ed under the chin. In the fraction of 

 a twinkling, the victim is drawn to the 

 waiting jaws in fulfillment of its hum- 

 hie destiny. 



There is the pretty mechanism of 

 that agile acrobat, the "hominy heat- 

 er" heetle which, when placed on its 

 hack, snaps itself about until it finally 

 lands on its feet. And there is the 

 great hairy mop of a tongue with 

 which the stag beetle laps up the sap 

 that flows from the tender twigs crush- 

 ed by the huge mandibles. 



Even the ubiquitous mosquito holds 

 many beautiful revelations for the mi- 

 croscopist. The two fluffy tufts form- 

 ing the antennae of the male are well 

 worth your attention. Although these 

 are of so odd a shape scientists tell 

 us that they are organs of hearing. 

 This was suggested as early as 1855. 

 Mayer, in 1874, led by the observations 

 of Hensen, conducted a series of exper- 

 iments with these beautiful plumose 

 antennae of the male mosquito to show 

 their auditor}' function. He fastened 

 a mosquito to a microscope slide and 

 then watched the hairs as he sounded 

 tuning forks near-by. When forks 

 producing vibrations of five hundred 

 and twelve per second were sounded, 

 some of the antennal hairs were 

 thrown into violent sympathetic vibra- 



The wings also hold a pretty secret. 

 It is for you to verify or to disprove 

 the existence of a structure that ap- 

 pears to exist on a wing in one of my 

 slides mounted a number of years ago. 

 It is- from one of the Anopheles, and 

 its picture shows that butterflies and 

 moths have no monopoly of scales on 

 their wings. The interest, however, 

 centers on the fringe of scales along 

 the hind edge. The next picture shows 

 a portion of this fringe greatly enlarged 

 and carefully drawn. In examining 

 this I was impressed by the apparent 

 insertion of the scales along the edge. 

 This fringe appears to consist of three 

 rows of scales. Those in the bottom 

 row are long. Those in the next row. 

 set higher on the membrane, are only 

 about half as long and overlap the first. 

 Those of the third row are still shorter, 

 and overlap the second. The scales in 

 the bottom row are straight, in the sec- 

 ond they are slightly convex while in 

 the top row they are decidedly convex. 

 Can this be a beautifully adapted me- 

 chanism for labor saving? It will re- 

 quire the careful examination of a 

 number of wings to determine this. If 

 it is found to be a common structure, 

 we can readily see that the down droop- 

 ing of this fringe on each upstroke of 

 the wing, and its straightening out on 

 each down stroke, each row bracing 

 the next lower like the various pieces 



THE SCALES OX THE WING OF A MOSOUITO. 

 Ihe dark markirgs are produced by closer groupings of the scales. 



tion. This is no accidental circum- of 

 stance. The hum from the wings o: 

 the female mosquito produces this 

 same note. 



a laminated vehicle sprim 



w 



ill 



mean the saving of an enormous 

 amount of energy in the course of a few 

 minutes, when we consider that the 



