136 Mr. C. F. M. Swynnerton on Rejections [Ibis, 



in the presence of highly pungent smells, amounting almost 

 to a volatile discharge, and that short-tongued birds such 

 as Hornbilis apparently did their tasting by an intake 

 of breath which, so far, was equivalent to smelling). The 

 view seems to be confirmed further by the acceptance by a 

 Rock-Tlirush of aWeaver's egg painted blue, and its rejection 

 of it when a few brown markings were added, the similar 

 rejection by a Bulbul of its own egg when a few small brown 

 markings were added to it, and, if it be supposed that 

 brown-madder paint may smell worse than blue, by the 

 retention of eggs by Amblyospiza with much brown-madder 

 paint added. The fact that an egg, drilled but unblown 

 and already smelling unpleasant, was accepted by Bulbuls 

 and retained until I removed it two days later, might also 

 be regarded as bearing on the point. 



11. The Cuckoo's habit of removing one of the host's eggs 

 seemed sound. — In three or four cases I added an egg to a 

 clutch which already contained one accepted egg of the 

 wrong colour. In each case the addition was at once 

 followed by the rejection of one egg. Thus, at a time 

 when the nest of the indiscrimiuatiug pair of Layard^s 

 Bulbuls I have referred to above contained two of the 

 birds' own eggs (fig. 11) and one of Telephonus senegalus^ 

 I added a fourth egg — a white egg of Hyphantornis jamesoni 

 (fig. 3), for which the Telephonus egg had been substituted 

 more than twenty hours before — I found shortly afterwards 

 that the Telephonus egg had been ejected. As both the 

 Shrike's egg and the Weaver's had previously been adopted, 

 it was probably only the fact that there were now four eggs 

 instead of three that caused the birds to reject one of 

 them — and only one. A Yellow-streaked Bulbul adopted 

 (quite likely, however, only temporarily, for I watched her 

 examine it well) a Coly's egg; but on my putting back 

 her own eg^, making three eggs in the nest instead of 

 the original two, she at once on her return flew back to 

 her mate, and one of the birds returned, picked up the 

 Coly's egg in its bill after a good deal of fumbling and 

 trouble, and flew off with it, gradually swerving towards 



