112 REPORT 1855. 



miglit be inspected during night and day. Delicate thermometers were so con- 

 structed as to be readily applied to any particular bee or cell. The following are the 

 principal results : — 



1. Temperature is one, if not the sole element, in determining the sex of the queen. 

 Huber ascribed the development of a queen from a neuter to special feeding, but no 

 microscopic or chemical test can detect any difference of food. The author, however, 

 found that the temperature of the royal cell was always higher than that of the 

 neighbouring cells, the difference of temperature being maintained by the increased 

 respiration of the bees clustering on the cell. The cell is also built out from the 

 plane of the comb, so as to admit of a special temperature being maintained. 



2. The queen or perfect female is always developed from an egg which, with ordi- 

 nary treatment, would have produced a neuter. The belief has hitherto been, that 

 the egg, from which the queen is ordinarily hatched, is different from the others, and 

 that the power of developing a female from a neuter is altogether abnormal. This 

 power, however, instead of being 'exceptional, is the normal method of producing 

 queens. 



3. The drones or males are hatched from eggs, which, without special treatment, 

 would have produced neuters. 



4. All the eggs laid by the queen are sexless, or rather bisexual. This follows 

 from the last two results. It has been hitherto understood by naturalists that the 

 queen lays three kinds of eggs, corresponding to the triple distinction of male, 

 female, and neuter. The observations of the author lead to the conclusion that 

 there is but one kind of egg, and that it depends on external circumstances which 

 sex is to be evolved. The instinct of the bees determines the circumstances suitable 

 for each sex, temperature being one, if not the sole determining condition ; and, by 

 respiration, they have the power of limiting a special temperature to a circumscribed 

 space. That a female should be developed from a neuter does not now appear so 

 startling ; but, at the first announcement, the discovery was received with incredulity, 

 and declared to be a miracle in nature. The wonder is much lessened, now, that it 

 is admitted, that the neuter is only an undeveloped female. The development of a 

 male from an egg that would, in other circumstances, have produced a neuter or a 

 female, is, however, a fact of a different order. The mass of the observations were 

 directed to the determination of this point, which may have an important bearing on 

 the development of life in general. The result arrived at is not altogether destitute 

 of analogy. It has been found that a plant which, under certain conditions of 

 light and temperature, produces only female flowers, may, by altering these condi- 

 tions, produce flowers of an opposite sex. Weber's discovery of traces of bisexuality 

 as a normal fact, even in the higher mammalia, also countenances the doctrine. 



5. There is a polar development of instinct in determining sex. When the 

 instinct of the colony is excited to produce a queen, there is, at the same time, an im- 

 pulse to produce drones. When the queen is removed from a hive, the colony 

 begin to hatch, at the same time, both males and females. This polarity of instinct 

 is still more remarkably displaj'ed by inserting drone brood in a hive which has still 

 a reigning queen. The presence of male brood excites the instinct to produce 

 females, and royal cells are immediately commenced, though, from the presence of 

 the queen, the attempt is abortive. 



6. The males, in the normal condition of the hive, are hatched in large cells, and 

 the neuters in small ones ; but when the drone instinct is excited while there are no 

 e'Tgs in the larger cells, the drones are hatched from eggs in the smaller ones ; and, 

 in this case, they are much smaller than ordinary drones, though their organs are 

 quite perfect. These small drones were observed by Huber, but he ascribed them 

 to retarded impregnation. The author repeated Huber's experiments on retardation, 

 but obtained a different result. He however could produce small drones at pleasure, 

 by determining the instinct of the hive to the production of drones. 



Singular Mortality amongst the Swalloiv Tribe. 

 By Edward Joseph Lowe, Esq., F.R.A.S., &)-c. 



There has seldom been recorded a more singular circumstance than the mortality 

 amongst the swallow tribe, which occurred on the 30th and 31st of May in the 

 present year. 



