INTRODUCTION. xix 



in the sand to be hatched by the heat of the sun. The 

 Megapodidse appear to lay their eggs m society. Most 

 birds breed but once in the year. A few, chiefly among 

 the Insessores, have two (or even more) broods; but 

 in India, I think, fewer in proportion than in colder cli- 

 - mates. The time of incubation varies pretty much 

 according to size, the smallest eggs being the most quickly 

 hatched. The males of many birds take their turn, in 

 the office of incubation and feeding the young, with the 

 females. These birds, during incubation, lose the feathers 

 of the middle of the breast and abdomen, by which the 

 warmth of their bodies is m.ore fully communicated to 

 the e2:o!:s. 



In most of the Gallinace^, and many of the Grallatores 

 and Natatores, the young on exclusion from the egg, are 

 covered with down, run at once, and are capable of picking 

 their own food. Others are hatched more or less naked, 

 and perfectly helpless, and have to be fed by their parents 

 for a longer or shorter period, even after they have 

 left their nests and are able to fly. The young of some 

 birds are fm-nished with a horny tip to the bill to enable 

 them to break the shell, and this falls oiF afterwards. After 

 exclusion from the egg, the young are diligently fed by 

 both their parents, and quickly assume their first plumage, 

 the feathers of the wings being early developed, by which 

 they are enabled to leave the nest, if alarmed, before 

 their full plumage is perfected. The fseces of the young 

 of most of the Insessores is removed by the parents, and, 

 being enclosed by a thin pellicle, can be taken up and 

 thrown out without breaking ; many birds are stated at 

 first to swallow the faeces. In most Fissirostral birds 

 and some others, the faeces have not this pellicle, and are 

 left in the nest, as voided by the young. "When able to fly, 



