BEES, WASPS, ANTS, ETC. 505 



the helpless young by the adult insects is something truly marvellous. In some of the 

 families this merely consists in placing the egg in the proper situation. It may be in 

 the substance of a leaf, or twig, or branch, where an abnormal vegetable growth will 

 take place, within which the larva can live and find nourishment ; it may be either 

 upon or within the body of another insect upon which the larva is to live parasitic-ally ; 

 or, again, within the nest of some other insect, from which the larva can sponge its 

 living. In each of these cases the instinctive care of the parent is of a higher grade 

 than would appear at first sight. With the gall-making species it is necessary that 

 the egg be laid in a particular part of the proper food plant. Each parasitic species 

 infests only certain other insects, and no more eggs are laid within or upon the para- 

 sitized insect than can be fully developed. With the guest insects the egg must be 

 laid in the proper nests, else they, or the larvae which hatch from them, will come to 

 gi-ief. All these, however, are simple exhibitions of instinct compared with what we 

 find in several of the higher families. Here a nest, often very elaborate in construc- 

 tion, is prepared for the reception of the egg. And then either a store of food sufficient 

 to bring the young insect to maturity is placed with the egg in this nest, or the wants 

 of the young receive daily attention. What is perhaps more wonderful than anything 

 else in this connection is the fact that with many species this care of the young is not 

 given by either of the parents, but by other individuals which are sterile. These 

 individuals bear a certain relation to the young under their care, which has been aptly 

 expressed as that of maiden aunts. It is an interesting fact that these helpless foot- 

 less larvae are developed from embryos which at a certain stage possess legs. This 

 indicates that the legs have been lost through disuse, and that these insects are the 



^j d? 



descendants of those which possessed legs in their larval state. 



When the larvae are full grown they transform to inactive pupae, which have all 

 the limbs of the perfect insects enclosed in distinct sheaths, and folded upon the 

 ventral aspect of the body. With many species the larva, before transforming, spins a 

 cocoon about its body. With some this cocoon is composed of comparatively loose 

 silk, and resembles to a certain degree the cocoon of a lepidopterous insect. In others 

 the cocoon is of a very dense parchment-like texture ; and in still others it resembles 

 a very delicate foil. 



The adult insects are usually very active creatures. In this state as a rule they 

 take but little nourishment, and this consists almost entirely of the nectar of flowers 

 and the sweet excretions of plant-lice and bark-lice. Hymenoptera may be seen con- 

 stantly collecting food from flowers or destroying and carrying off other insects. 

 There are, however, some species, notably ants, in Avhich the adult state may last 

 many years, during which time they are constantly active and require considerable 

 food. 



As with other insects it is the rule in the Hymenoptera that the union of two sexes 

 is necessary to reproduction. Still instances of parthenogenesis are common through- 

 out the entire order. Many make sounds. The humming of the bees is familiar to 

 all. Landois has studied these sounds and the apparatus by which they are produced. 

 In the hive-bee a sound is produced by the vibration of the wings during flight ; but 

 the true voice of the insect is produced by the band-like margins of the stigmata, both 

 thoracic and abdominal. In the bumble-bees the abdominal stigmata are here the 

 chief producers of sound, and they present a rather complicated construction. Each 

 stigma is an oval aperture surrounded by a chitinous ring ; it is situated beneath a 

 hemispherical cup divided by a slit into two nearly equal parts, and is furnished with 



