tions; the man who uses all his leisure in scouring woods and fields, swamps and running waters, for its wealth of insect life; who works in good weather and bad, for whom the woods at night hold no terrors when in pursuit of specimens? What about the collector? Of a surety he is entitled to rank among the elect, for without him the systematist would have little to work with and the student of insect ecology but a poor basis for his branch of the science. It is the collector who in the past has formed the body of all our entomological societies, and now forms the working majority of most of them. It is the collector upon whom the science rests as a foundation and he is entitled to rank by himself, although aside from this he may and often does belong to one of the other divisions as well.
Now, dropping the entomologist for the moment, let us consider the insects themselves, and here we find their influence extending in every direction; sometimes to our benefit, more often to our injury. Those that affect us injuriously we are able to subdivide into those that attack us directly either as parasites or merely as a source of food supply, and those that prey upon our crops, supplies or farm stock. And even the list of directly injurious forms is not a small one for, to begin with, there are no less than three species of sucking lice that attack the human animal and are confined 
Fig. 1. A head louse. to him, favoring his head, and other hairy regions, and his clothing when he wears any. It is an interesting matter for reflection that the egg laying habit of the body-louse is an adaptation that must have required ages to develop and that could not even begin to develop until man wore clothing of some kind.
And wherever man goes wholly or partly unclothed, he shares with other animals the danger of becoming infested with creatures like bots, screw worms and other dipterous maggots, or penetrating insects like jigger fleas and their allies. Man, then, stands in the relation of host to a not inconsiderable number of insects species, only a few of which, however, are really dependent upon him.
But as prey, his usefulness to insects is infinitely greater. In his home a variety of bloodsuckers have established themselves; even in his bed they may be found, and they range from the reasonably sized creatures found in the temperate regions to the infinitely more formidable creatures found in the tropical countries, where the bites often produce unpleasant and even dangerous results.
Where man has hairy pets, like cats and dogs, the fleas that infest them primarily often attack him as a compliment, and in some sections of the world and of own country fleas are not insignificant either in numbers or effects.
