126 



Marvels of the Universe 



the complexit}' of the machinery used in the 

 process. 



The accompanying photo-micrograph 

 shows the open mouth of a worker--\\asp 

 with the various organs in position, and 

 which are so unhke the mouth-parts of man 

 and other higher animals that it is ahnost 

 impossible to make any adequate comparison 

 between them. 



The large horny jaws, or mandibles, seen 

 on each side work sideways, not up and 

 down like our own, and serve alike 

 to rasp wood-fibres for nest-building 

 purposes, to bite into the choicest plum 

 or pear in the orchard, or to cut off 

 the wings of a captured flj^ before it is 

 carried off to the nurserj'. \^'hen the 

 wasp is biting hard substances, however, 

 the transparent tongue and other deli- 

 cate organs of the mouth are withdrawn 

 into a receptacle within the lower part of 

 the head. 



The upper lip, if we may call it such, is 

 a simple scale-like body, while the lower lip 

 (to complete the comparison) is of a much 

 more complex structure. It is provided 

 with a broad transparent tongue, very 

 different from that of a bee, a butterfiv, or a moth, for it is but few flowers that the wasp visits 

 in search of their nectar. 



Attached to the sides of the delicate fnur-lobed tongue, which is covered with minute hairs 

 and bears a lai-ge gland at the tip of each lobe, is a pair of small four-jointed feelers, which serve 

 as organs of sense. Outside the tongue and its feelers are two other complex organs, each bearing 

 sensory hairs and a si.x-jointed feeler, and we may conventionally call them the modified lower jaw, 

 the mandibles representing the upper jaw. 



^^'hatever work the wasp has to perform, whether it is carrying a little stone out from the 

 building site of the nest, biting through strong roots, manufacturing paper-pulp, robbing the 

 orchard, or stealing tiny portions of meat from the butcher's shop — which it sometimes prefers to 

 its more lawful prey, the flies — these are the tools which it employs. Just what function the 

 delicate feelers and sensitive hairs serve, and which are associated with the senses of touch, 

 smell, taste, etc., science is as yet quite unable to explain ; especially as they are probably 

 connected with senses which are not analogous with our own. 



The head, too, bears a pair of conspicuous feelers, and these again possess comple.x sensory 

 functions. A glance into a thriving nest leaves no doubt in the mind of the observer that these are 

 the organs by which communication is made one with another ; probably, too, they serve the sense 

 of hearing. The large compound eyes, with their numerous lenses, so unlike our own, are likewise 

 puzzling organs, especially as on the top of the head between these large eye-masses three simple 

 e3'es are to be found. Why the wasp should need three single eyes and two large' compound 

 eye-masses with thousands of lenses, each of which can receive an image, is, judged from man's 

 standpoint, an inexplicable problem. 



WASP-STI.NG AND NEEDLE 



To show the fineness of the wasp's sting it is here photographed 

 threaded through the minute eye of a No. 16 needle. 



