DWELLINGS. 203 



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 Antlwphora to endeavour 

 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 resistant wall.^ 



The other animals of which I have to speak are 

 genuine masons, who prepare their mortar by temper- 

 ing moistened earth. 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 utilised, and tohave an 

 enclosed 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 applying earth more or less mixed with 

 chopped hay against the walls which are to support 

 the edifice. At the summit of the construction a hole 

 is left for entry and exit. During the whole of its 

 sojourn in our country the Swallow uses this dwelling, 

 and even returns to it for many years in succession, 

 as long as its work will support the attacks of time. 

 The faithful return of these birds to their old nest has 

 been many times proved by attaching ribbons to their 

 claws ; they have always returned with the dis- 

 tinctive mark. 



The Chalicodoma, whose name of Mason Bee in- 

 dicates the industry it exercises, is a hymenopterous 

 relative to our Bees, long since carefully studied by 

 Reaumur. It does not live in societies like the latter, 



1 Latreille, "Observations sur I'abeille parietine {Anthophora parie- 

 Una)," Annales du Musium d'Hist. Nat., t. iii., 1804, p. 257. 



