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APPENDIX. 
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 assumes his post and duties for the same period. On the duration of this 
guard some doubts may reasonably be entertained, but of its existence ample evi- 
dence was 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 entering or quitting 
the hive ; the sentinel constantly resuming his station immediately after the passage 
had been effected. That it was the same bee which had withdrawn that again 
took his station in the opening, could not be mistaken ; for his withdrawal was 
only into the cavity on the side of the hole, in which his head was generally in 
view during the brief interval while the other was passing ; and that head again 
immediately started forwards into the passage. 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 constanriy 
eluded the aim taken at him, and it was therefore impossible to determine with 
certainty whether the current reports concerning him were or were not founded in 
fiict. 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 repeatedly made at his body, approached the foreign 
substance to taste it, and evidently disliking the material he withdrew into his 
hive. The hole was watched to see what would be the result of this investigation 
of the substance, and 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 mandibles, 
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 completely relieved the inhabitants from its 
annoyance. 
If the existence of such a sentinel as has just been described can safely be 
admitted, his utility would be unquestionable, as being at all times prepared to 
encounter a straggling stranger, or to give warning of the approach of a more 
numerous body of foes. Such foes actually exist in moderately sized black ants, 
which sometimes in small, and occasionally in large, bands attack the hive, and 
between which and the industrious bees desperate conflicts often take place. Id 
these struggles the bees generally obtain the victory; but they are occasionally 
mastered by the overpowering numbers of their opponents. 
