DEFENCE AND SANITATION OF DWELLINGS. 239 



which lives in a wild state in South America. They 

 place their combs in the hollow of a tree or the cleft 

 of a rock ; they fill up all the crevices and only leave 

 a round hole for entry. And even this they are 

 accustomed to close every evening by a small par- 

 tition, which they remove in the morning. This door 

 is shut with various materials, such as resin or even 

 clay, which the bees bring on their legs as those of 

 our own country bring pollen. 



All these facts were observed with great exactness 

 in a swarm given in 1874 by M. Drory (who during a 

 long period of years studied every Brazilian species 

 of Melipona at Bordeaux) to the Jardin d'Acclima- 

 tation. It was even seen that the door might be put 

 up under certain circumstances in open day, as for 

 example, when a storm or sudden cold delays the 

 appearance of the workers. If one of them happened 

 to be late it had to perforate the partition, and the 

 hole was then stopped up again. 



Fortifications of Bees. — As these facts take place 

 always they may be called instinctive ; but that is 

 not the case with regard to defences elevated with 

 a view to a particular circumstance, and which dis- 

 appear when the danger to which they correspond 

 disappears. Such are the labours of the bees to 

 repel the invasions of the large nocturnal Death's- 

 head Moth. (Fig. 42.) He is very greedy of honey, 

 and furtively introduces himself into the hives. Pro- 

 tected by the long and fluffy hairs which cover him, 

 he has little to fear from stings, and gorges himself 

 with the greatest freedom on the stores of the swarm. 

 Huber, in his admirable investigations,^ narrates 

 that one year in Switzerland numbers of hives were 

 1 Huber, NouvelUs observations sur les AbeilUs. 



