INDUSTRIES OF ANIMALS. 



603 



tain animals, whose dwelling participates in the nature of a hol- 

 low cavern, make additions to it which claim a place among the 

 constructions with which we are now occupied. 



The Anthophora parietina is in this group : it is a small bee 

 which lives in liberty in our climate. As its name indicates, it 

 prefers to frequent the walls of old buildings, and finds a refuge 

 in the interstices, hollowing out the mortar half disintegrated by 

 time. The entrance to the dwelling is protected by a tube curved 

 toward the bottom, and making an external prominence. (Fig. 

 7.) The owner comes and goes by this passage, and as it is curved 

 towards the earth the interior is protected against a flow of rain, 

 while at the same time the entry is rendered more difficult for 

 Melectes and Anthrax. These insects, in fact, watch the departure 

 of the Anthophora to endeavor to penetrate into their nests and lay 

 their eggs there. The gallery of entry and exit has been built 

 with grains of sand, the debris produced by the insect in working. 

 These grains of sand glued together form, on drying, a very re- 

 sistant wall.* 



The other animals of which I have to speak are genuine ma- 

 sons, who prepare their mortar by tempering moistened earth. 



FIG. 7. HOMES OF MASON BEES. 



Every one has seen the swallow in spring working at its nest in 

 the corner of a window. It usually establishes its dwelling in an 

 angle, so that the three existing walls can be utilized, and to have 

 an inclosed space there is need only to add the face. It usually 

 gives to this the form of a quarter of a sphere, and begins it by 



* Latreille, '' Observations sur 1'abeille parietine (Anthophora parietina)" Annales du 

 .Museum d'Hist. Nat., t. iii, 1804, p. 257. 



