214 Twelve Months With 



bills, and their nesting habits also seem to indicate 

 their reptilian origin. Few of these birds build 

 elaborate nests. Many merely lay their eggs in 

 the sand or gravel, after the manner of a snake 

 or turtle, but they have made some advance over 

 their ancient progenitors in the matter of incuba- 

 tion, as they sit upon their eggs, and do not depend 

 upon the sun to hatch them. 



The higher we go in the order of nature, the 

 greater is the attachment to home and family, and 

 the more highly developed the species of birds, 

 the more attention do we find given to the nest 

 and eggs. 



In most cases perhaps the nest should be called 

 the nursery rather than the home, because, with 

 few exceptions, there is little real abiding affection 

 for nest, young or mate. Among our birds only 

 the eagle and the osprey mate for life. While 

 the higher order of our song birds mate for the 

 season, if one of a pair disappears during the 

 nesting time, its place is usually filled by another 

 within a few hours, and among the lower orders 

 of birds, polygamy is common. 



The greatest devotion to home and family is 

 found in those species whose young are helpless 

 when hatched. They are called altrices or altri- 

 cials, as distinguished from praecoses or precocials, 

 who run or swim as soon as they are born. Altrices 

 is derived from the Latin altrix, meaning "to 

 nurse." The precocials therefore may be called 

 chicks, and the altricials, nestlings. Among the 



