470 



ANIMAL LIFE-HISTORIES 



This is also true of the Tree- Sparrow {P. montaniis). During 

 the nesting season the Chaffinch [Fringilla coelebs) abandons 

 its diet of seeds and berries in favour of animal food, devoting 



Fig. ggo. — House-Sparrows {Passer doijiesticus) feeding their Young 



special attention to the little caterpillars found in buds and 

 flowers, which are also adapted to the tender digestions of the 

 nestlings. Linnets {Linaria cannabina, fig. 991) are consistent 

 vegetarians, but the seeds and other vegetable matters, with 



Fig. ggi. — A Nest of Linnets {Lhiaria camiahhid, 



which the young are fed, first undergo a softening process in 

 the crops of the parents. A curious adaptation for the benefit 

 of the young is found in Pigeonj, which produce a special sort 

 of "infants' food" popularly known as "pigeons' milk". This 

 is not, however, a secretion, but consists of curd-like flakes 



