Natural History , #c. 641 



entire. It has a leaning towards the trigona, but its general appear- 

 ance is entirely that of a melipona, approaching very closely to that 

 of melipona favosa, Latr., apisfavosa, Fab. 



Some curious anecdotes are related by the possessors as to the 

 manners of these bees ; one of which deserves to be recorded. They 

 assert, that at the entrance of each hive a sentinel is placed to watch 

 the outgoings and incomings of his fellows, and that this sentinel is 

 relieved at the expiration of twenty-four hours, when another as- 

 sumes his post and duties for the same period. Of the duration of 

 this guard some doubts may be reasonably entertained ; but of its 

 existence ample evidence has been obtained by repeated observation. 

 At all times a single bee was seen occupying the hole leading to the 

 nest, who, on the approach of another, withdrew himself within a 

 small cavity apparently made for this purpose on the left hand side 

 of the aperture, and thus allowed the passage of the individual en- 

 tering or quitting the hive, the sentinel constantly resuming his 

 station immediately after the passage had been effected. During 

 how long a time the same individual remained on duty could not be 

 ascertained ; for, although many attempts were made to mark him 

 by introducing a pencil tipped with paint, he constantly eluded the 

 aim taken. With the paint thus attempted to be applied to the bee 

 the margin of the opening was soiled, and the sentinel, as soon as 

 he was free from the annoyance he suffered from the thrusts repeat- 

 edly made at his body, approached the foreign substance to taste it, 

 and, evidently disliking the material, he withdrew into his hive. A 

 troop of bees was soon observed to advance towards the place, each 

 individual bearing a small particle of wax, or of propolis, in his man- 

 dibles, which he deposited in his turn upon the soiled part of the 

 wood. The little labourers then returned to the hive, and repeated 

 the operation until a small pile rose above the blemished part, and 

 consequently relieved the inhabitants from the annoyance*. 



9. MEAN METEOROLOGICAL RESULTS. 



M. Bouvard, from the examination of more than a hundred thousand 

 observations, made at the Royal Observatory of Paris, and em- 

 bracing a period of eleven years, deduces the following conclusions : 

 The mean height of the barometrical variations is O mm .15. 



That from nine o'clock in the morning till three in the afternoon, 

 the variation from the mean height is about double of that from three 

 to nine in the afternoon. Hence it is necessary, in determining the 

 mean pressure of the atmosphere, to pay attention to the times of 

 observation. During the months of February, March, and April, 

 the variation from the mean is greater than in the months of Novem- 

 ber, December, and January ; and that during the rest of the year 

 the barometer, between the hours of nine A. M. and three P. M., 

 only suffers slight oscillations about the mean height. The height 



* Beechey's Voyage, App. p. 613, 



