350 



Marvels of Insect Life. 



Like those of the stick-Insects, the egg of the walking-leaf is enclosed in a capsule 

 which is so much like a ribbed seed such as is produced by many plants of the parsnip 

 famih^ that one entomologist who has made a careful investigation into the structure 

 of the capsule of one species,^ expresses his belief that almost every botanist examining 

 a thin section of this capsule would declare that he was looking at a vegetable 

 production. 



All these leaf-Insects are green after their infancy, but it is impossible to go 

 further and say what sort of green, for each individual frequently changes the 

 particular tint of green, according to his food and surroundings, so that he may 

 be alternately yellow-green, red-green, brown-green, blue-green, or any other kind 

 of green. The natives of the places in which they are found shake their heads 

 when told that the walking-leaf comes from an egg like other Insects. It is their 



fixed belief that a 

 leaf-bud develops 

 into this creature 

 with legs, quits its 

 attachment to the 

 twig, and walks 

 about. The likeness 

 to real leaves is so 

 great that even the 

 Insects themselves 

 are deceived by it, 

 and have been known 

 to begin feeding 

 upon their com- 

 panions before they 

 discovered — prob- 

 ably by the differ- 

 ence of taste — they 

 had made a mistake. 

 That this was not 

 due to cannibalism is shown by the fact that the attacks never proceeded far 

 enough to injure the bitten one, but onl}^ far enough to make the deception 

 appear more convincing. 



The Fly that Causes Sleeping-Sickness. 



The tsetse-fly has long been familiar to readers of books on Zululand and other 

 parts of Tropical Africa, where it proved a great scourge by killing off the buffaloes, 

 oxen, and horses. From the sixteenth century onwards, explorers had noted this 

 circumstance, mainly from information derived from the natives, who belie\'ed 

 that the disease of their cattle — the nagana or fly-disease, as it was called — -was due 

 to the attack of the fly. The theory was that the sucking organ of the fly had 

 a poison-gland at its base, some of whose contents were poured into the wounds it 

 made, and that such a " bite " was followed by the illness of the animal that had been 



^ PhvUium crurifolium. 



Photo by] 



Male Walking-Leaves. 



[H. Baslin. 



Tliese are males of the species whose temal'^ is shown on the previous page. In the second figure 

 will be seen the wing-covers, so small as to be quite useless for covering the wings. It wiU also be 

 noticed that the male has long antennae, whilst in the female they are very short. 



