70 The Ottawa Naturalist. [July 



jackets'' and "white-faced hornets" whose stings are so much 

 feared by marauding youngsters bent on destroying their 

 colonies. They are the original pulp and paper-makers, and 

 the nests of some species are very large and conspicuous objects 

 attached to trees or buildings. Some of the species construct their 

 homes in hollow trees or in holes in the ground. No inatter 

 how large a nest may be, it results from the initiative energy of 

 one individual and is the work of one season, at the close of which 

 it is deserted. The founder is a fertilized female which, after 

 passing our long cold winter, say November to April inclusive, 

 in a rotten log or other suitable retreat, emerges with the return of 

 revivifying spring and at once starts the foundation of a colony. 

 Gnawing off a little bundle of fibres from the nearest old fence, 

 telegraph pole, or other convenient dead wood, she masticates 

 and works them into a pulp with which a cell is commenced. As 

 soon as a few cells are completed an egg is placed in each, and 

 dailv the nest grows larger by the constant addition of cells and 

 protective covering. After a few days the eggs commence to 

 hatch and the mother wasp has to toil more assiduously than 

 ever to keep her establishment going. As the days lengthen and 

 grow warmer so are her labours prolonged and intensified. In 

 addition to paper-making and house-building, she has now to 

 provide suitable nutrition for a constantly increasing family of 

 voracious larvae. The food for these consists chiefly of macerated 

 insects and each grub, hanging head downward in its cell has 

 to]^be separately fed. Flies form the chief prey of the wasp and, 

 fortunately for her, these are now abundant. As so many of 

 the diptera are obnoxious, the labours of the wasp tend to benefit 

 us indirectly. Juices of fruits, especially of over-ripe or injured 

 ones, are attractive to the yellow-jackets, but any loss which thev 

 mav inflict in gathering the sugary secretions is abundantly 

 compensated for by the destruction of innumerable flies attacking 

 plants and animals. At the end of four weeks from oviposition 

 the voung wasps have passed through their various stages and 

 are able henceforth to assist in the various duties of the establish- 

 ment. They are all sterile, or imperfectly developed females, 

 which are known as w^orkers. and which are smaller than the 

 queen mother. The latter is gradually relieved from the gather- 

 ing of building and food supplies, and remains chiefly in the nest, 

 placing her eggs in the cells as they are built or emptied. The 

 continuance of the colony is now more assured than when the 

 queen was exposed to the dangers which daily beset her when 

 flving abroad. Workers are now constantly maturing and the 

 nest increases in size, until it may be as large as a football, and 

 contain several discs of comb suspended one below the other, 



