350 niRUNDINIDiE. 



Its nest also, though constructed of the same materials as 

 the Swallow's, is of a very clififerent shape, the mud-walls 

 being raised to meet and be partly borne by the shelter 

 under which it is built, leaving only an opening sufficient for 

 entrance and exit. Furthermore the nest never seems to 

 be placed within a chimney or room, but is either fixed 

 beneath a porch or archway or on the outside of a building, 

 most commonly under the eaves, and not unfrequently in the 

 upper corner of a window — sometimes even resting partially 

 against the glass. Its shape is approximately that of the 

 half or the quarter of a hemisphere, but never hemi- 

 spherical as has so often been said. Built as it almost 

 always is without any prop to support its weight, its founda- 

 tions require no ordinary care, and a week or more is often 

 occupied in laying them, after frequent trial of various spots 

 — the builders clinging to the wall by their feet and assist- 

 ing themselves with their tail to retain their precarious hold, 

 while depositing the materials which as just said, are similar 

 to those used by the Swallow and are collected in the same 

 way. Moreover the nest is at first very gradually constructed, 

 the lower layers of mud being left to dry and harden before 

 more are added. When the base is become firm, the 

 remainder is often finished with great rapidity, and the 

 interior, being furnished with feathers and a few bents or 

 fine straws, forms the nuptial couch of the owners who 

 frequently occupy it at the same time.* 



* The curious and rather ludicrous mistake of an eminent French biologist 

 must here be noticed since it has led other ornithologists astray. On March 

 7th, 1870, the late M. Pouchet announced to the French Academy of Sciences 

 {Coniidcs Rendus, Ixx. p. 492) that within the last half-century some of the 

 " Ilirondelles'" of Rouen had wholly changed their style of architecture, adapt- 

 ing it to that which had been lately introduced liy man. In the new part of 

 the city he observed that their nests were built on a very diiferent (and, as 

 seemed to him, an improved) plan from that which was still followed in the 

 older part. Hence he inferred that the birds possessed greater intellectual 

 faculties than had been thought, since they were able to avail themselves of the 

 advance of civilization. But the simple explanation of a circumstance so extra- 

 ordinary was not long delayed, for on July 4th, of the same year, M. Noulet 

 was able to shew that his distinguished predecessor had been a little hasty. It 

 was true, said he (op. cit. Ixxi. p. 78), that the nests in the two pai"ts of the 

 city differed as had been described, but then the one belonged to Hirondclles de 



