SOCIALES BUMBLE-BEES 55 



society. The larvae in the first cell, as they increase in size, 

 apparently distend the cell in an irregular manner, so that it 

 becomes a knobbed and rugged, truffle-like mass. The same 

 thing happens with the other cells formed by the queen. Each 

 of these larval masses contains, it should be noticed, sister-larvae 

 all of one age ; when full grown they pupate in the mass, and 

 it is worthy of remark that although all the eggs in one larval 

 mass were laid at the same time, yet the larvae do not all pupate 

 simultaneously, neither do all the perfect Insects appear at 

 once, even if all are of one sex. The pupation takes place 

 in a cocoon that each larva forms for itself of excessively 

 fine silk. The first broods hatched are formed chiefly, if not 

 entirely, of workers, but small females may be produced before 

 the end of the season. Huber and Schmiedeknecht state that 

 though the queen provides the worker-cells with food before the 

 eggs are placed therein, yet no food is put in the cells in which 

 males and females are produced. The queen, at the time of 

 pupation of the larvae, scrapes away the wax by which the 

 cocoons are covered, thus facilitating the escape of the per- 

 fect Insect, and, it may also be, aiding the access of air to the 

 pupa. The colony at first grows very slowly, as the queen can, 

 unaided, feed only a small number of larvae. But after she 

 receives the assistance of the first batch of workers much more 

 rapid progress is made, the queen greatly restricting her labours, 

 and occupying herself with the laying of eggs ; a process that 

 now proceeds more and more rapidly, the queen in some cases 

 scarcely ever leaving the nest, and in others even becoming 

 incapable of flight. The females produced during the inter- 

 mediate period of the colony are smaller than the mother, but 

 supplement her in the process of egg - laying, as also do the 

 workers to a greater or less extent. The conditions that deter- 

 mine the egg-laying powers of these small females and workers 

 are apparently unknown, but it is ascertained that these powers 

 vary greatly in different cases, so that if the true queen die the 

 continuation of the colony is sometimes effectively carried on by 

 these her former subordinates. In other cases, however, the 

 reverse happens, and none of the inhabitants may be capable of 

 producing eggs : in this event two conditions may be present ; 

 either larvae may exist in the nest, or they may be absent. In 

 the former case the workers provide them with food, and the 



