128 THE NATUEAL HISTOEY 



The curious Rdaumur discovered the large eggs, or rather 

 pupcB, of these flies as big as the flies themselves, which he 

 hatched in his own bosom. Any person that will take the 

 trouble to examine the old nests of either species of swallows 

 may find in them the black shining cases or skins of the pupce 

 of these insects : but for other particulars, too long for this 

 place, we refer the reader to I'Histoire d'Insectes of that admir- 

 able entomologist. Tom. iv. pi. 11.^ 



LETTER XVI. 



TO THE SAME. 



Dear Sir, 



Selborne, Nov. 20, 1773. 



In obedience to your injunctions I sit down to give you some 

 account of the house-martin, or martlet ; and, if my monography 

 of this little domestic and familiar bird should happen to meet 

 with your approbation, I may probably soon extend my enquiries 

 to the rest of the British hirundines — the swallow, the swift, and 

 the bank-martin, 



A few house-martins begin to appear about the sixteenth of 

 April , usually some few days later than the swallow. For some 

 time after they appear the hirundines in general pay no attention 

 to the business of nidification, but play and sport about, either to 

 recruit from the fatigue of their journey, if they do migrate at 

 all, or else that their blood may recover it's true tone and texture 

 after it has been so long benumbed by the severities of winter. 

 About the middle of May, if the weather be fine, the martin 

 begins to think in earnest of providing a mansion for it's family. 

 The crust or shell of this nest seems to be formed of such dirt 

 or loam as comes most readily to hand, and is tempered and 

 wrought together with little bits of broken straws to render it 

 tough and tenacious. As this bird often builds against a per- 

 pendicular wall without any projecting ledge under, it requires 

 it's utmost efforts to get the first foundation firmly fixed, so that 

 it may safely cany the superstructure. On this occasion the 

 bird not only clings with it's claws, but partly supports itself by 



1 \M4moires pour servir d I'Histoire des Insectes, par M. de Riaumur, Paris : 

 6 vols, , 4to, 1734-42.] 



