Marvels of the Universe 



239 



The use of this position in Nature, becomes apparent with but Uttle consideration. It is for a two- 

 fold purpose : first to allow the fiy to commence taking its food at once, without change of posture, 

 and also for the purpose of allowing room for its eyes to look around in all directions to warn it of 

 approaching danger. 



The eye of these insects, being compound — bj- which it is meant it is composed of numerous 



limultaneously in almost 

 where it is shown lying 



% 4 A 





J^ 



facets (something hke four thousand), each furnishing an image — can see 

 an3^ direction : which explains wh\- it is so \-er\- difficult to catch a fly. 



The tongue, as a whole, can be studied by examining the photograph, 

 in front of and between the two clubs. It 

 is a two-lobed organ, both lobes simul- 

 taneousl}- acting as one, and being capable 

 of closing or collapsing hke the shutting-up 

 of an umbrella, and of ^\■^thd^awal, as a 

 snail retires into its shell. The entire 

 organ is really enclosed in an exceedingly 

 fine and deUcate membrane, which for some 

 reason is not easy to see or to photograpli 

 in the case of the House Fly. It is better 

 shown in the tongue of the Gadfly, where 

 the dehcate membrane, broken away in 

 parts, is distinctly visible covering the top 

 of the lobes. The object of this delicate 

 covering undoubtedly is to prevent dirt 

 getting into the suctorial tubes, which are 

 shown verj- plainly in the more highly- 

 magnified photograph of the same organ. 

 All these tubes, it will be seen, empty into 

 two main collecting tubes, one for each 

 lobe, by which the nutriment enters the 

 system of the fly. Before proceeding 

 further, it should be noted that the two 

 black wire-like-looking objects, one cur\'in'j 

 to the right and the other bending to the 

 left, at the lower part of the lobes, are not 

 tubes, but the supports of the tongue — 

 hke the framework of the umbrella — and 

 which serve to assist in the opening and 

 closing of the little organ. The extended 

 organ is well seen in another photograph, 

 which was prepared by a special method 

 without pressure. 



The tubes are ingeniously made, and merit a little close attention. Even a cursory glance at 

 the photograph shows that they are not solid, like pieces of brass tubing, but that they are formed 

 by a series of juxtaposed rings or ribs. These are believed to be formed of a gristle-like substance 

 so as to be somewhat elastic. Further, close inspection of the same figure will reveal the fact that 

 each rib (in the larger tubes) is not a complete ring, but only about three-quarters of the same — like 

 a horse-shoe, in fact. To convert the string of incomplete ribs into a continuous tube, a membrane 

 of exceeding delicacy not only covers the spaces between the rings, but stretches across their open 

 ends. A completed tube then, in section, would appear like a horse-shoe, where the heels have been 



I'hoU 



'''«] 











[A', 



, J. Hpittc. 





PART 



OF FLY 



•S FOOT 



WITH 



BACTERIA. 





A 



portion of 



the pad 



of a Fly's 



fool sfi 



owing 



how 



this 



insect 



conveys Bacteria, 



often of 



a pernicious kind. 



lo our 



food. 



The 



black 



patches and streaks are the 



Bacteria. 













