Marvels of Insect Life. 



Phnio by] 



\Luinsden. 



Pigeon Parasite. 



An example of the adaptation of 

 structure to habit. These Insects Hvp 

 among the plumage of birds, and arc 

 fitted for secure holding to their host. 

 The actual length of the Insert is 

 about onr -eighth of an inch. 



in any 

 of the backboned animals. 

 What may be termed the heart 

 (it is usually known as the 

 "dorsal vessel") is a series 

 of about eight connected sacs 

 extending one behind the other 

 from head to tail, and opening one 

 into the other by valves which 

 permit the blood to flow in one 

 direction only — from behind for- 

 wards. There arc no arteries or 

 veins, th(> blood lilhng vacnnt 



number. The hind-body bears no appendages, except 

 those connected with the function of reproduction. 

 Stings, where present, are moditications of these 

 organs. 



The limbs of mature Insects are all made up of 

 several joints, and it is remarkable that these joints are 

 constructed on the same principle as in backboned 

 creatures, and are extended or folded bv the contraction 

 of similar sets of muscles, though in the one case the 

 muscles are attached to the central bony portion, and 

 in the other to the chitinous exterior. The number of 

 joints in these limbs is not the same in all orders or 

 families of Insects. There is considerable variation in 

 the terminal section of the legs — the foot — which 

 normally consists of five segments, but may be reduced 

 to three or two. In caterpillars the only true legs are 

 the three pairs at the front end of the body : those in 

 the middle and at the hind extremity are unjoin ted 

 temporary structures. The jaws and sucking apparatus 

 of the mouth are seen by the process of development 

 within the egg to be essentially modified limbs. So 

 also are the feelers or antennae. 



The internal organs of an Insect mav be said 

 briefly to consist of the circulatory system, the organs 

 of nutrition, the nervous system, the breathing apparatus, 

 and the reproductive organs. The ner\'ous system 

 occupies the lower side of the body, the circulatorv 

 s\/stem the upper side, with the alimentary system 

 central. The circulatory system is of a simpler character 

 than is 

 t o b e 

 f o u n d 



Photr.hy] Brazilian Rhinoceros Beetle. \.i^- 5>^^ F-^-^- 



.•\nother example of the eccentric forms taken by the fore-parts of 'some of 

 the beetles. Here only the first horn is from the head, the massive two- 

 pointed erection behind it being from the fore-body. Natural size. 



