434 



Marvels of the Universe 



Various species of Ants eject a corrosive fluid known as formic acid, and the group of small beetles 

 known as Bombardiers have a somewhat similar defence. 



The last segment of the Bombardier's body bears a couple of glands which secrete an acid fluid 

 into a pair of little bladders. When the Bombardier is pursued by a larger beetle or other enemy, 

 muscular pressure appears to be exerted upon these bladders, with the result that there is a cracking 

 report and a little of the acid is ejected and turned to a bluish vapour on contact with the air. The 

 action may be repeated several times if the first explosion does not serve the purpose of repulsing 

 the enemy. 



The Bombardier is a small beetle, found chiefl}? along the shores of rivers, where it is often 



pursued by the larger Ground Beetles 

 which are carnivorous, and therefore 

 the Bombardier stands in some need of 

 special protection. Such a pursuit and 

 repulse is shown in our iUustration, 

 where both Beetles are shown twice 

 the actual size. 



STICK INSECTS 



BY K. G. BLAIR, B.SC, F.E.S. 



Stick Insects afford a beautiful 

 example of those animals which in 

 their bodily structure, combined with 

 the habit of remaining motionless, 

 bear so close a resemblance to some 

 inanimate object of their natural sur- 

 roundings that they very readily escape 

 notice, and consequent consumption, 

 by their enemies. As their name im- 

 plies, they resemble sticks and twigs 

 of the foliage in which they usually 

 dwell ; if disturbed, the resemblance 

 is made yet more close by their habit 

 of folding the limbs close to the body 

 with the forelegs straight out in front 

 and feigning death ; it is then difficult 

 to realize that one is deahng with a 

 living insect and not with a piece of 

 dead twig. In connection with this 

 habit should be noticed the shape of 



^V 



Photo !)!/] [F. Noad Clark. 



EGGS OF STICK INSECT. 



The eggs are shown about nine times larger than the real size. They 

 have a close resemblance to seeds. Each is provided with a lid. which the 

 newly-hatched "Stick" pushes off, as shown in one of the upper figures. 



the front legs. At the base they are very slender, but about the middle of the first joint they 

 thicken rather suddenly and then taper away to the foot. When they are held straight out in 

 front in the proper "stick" attitude, the head fits exactly into this hollowed part and the eyes 

 are able to look out over the base of the leg, while the continuity of the stick-hke body remains 

 uninterrupted. 



Stick Insects are found throughout the warmer parts of the world, but the kind here illustrated 

 comes from India. Though many of its relatives possess wings, this species is wingless in all 

 stages. They are nocturnal in their habits, remaining motionless among the twigs of their food- 

 plant during the day. They walk rather slowly, and before coming to rest have a peculiar habit 



