B. VI.] THE HISTORY OF ANIMALS. 139 



that from their proximity they look like a chain of nests. 

 Among the birds which make solitary nests, the hoopoe 

 makes no real nest, but lays its eggs in the stumps of hollow 

 trees, without building at all. The coccyx 1 lays its eggs in 

 houses and holes in rocks. The tetrix, which the Athenians 

 call " urax," makes no nest on the ground or in trees, but 

 in herbaceous plants. 



CHAPTER II. 



1. THE eggs of all birds are alike and have a hard shell, if 

 they are produced by sexual intercourse and are not decayed, 

 for domestic fowls sometimes lay soft eggs. Birds' eggs* are 

 two-coloured, externally white, internally yellow. The eggs 

 of birds inhabiting the sides of streams and lakes differ from 

 those living on dry land, for in the eggs of aquatic birds the 

 yolk bears a much larger proportion to the white. 



2. The colours of eggs vary in different kinds of birds. 

 Some have white eggs, as pigeons, partridges ; some yellow, 

 as those inhabiting streams ; others are spotted, as those of 

 the meleagris 2 and phasianus; 3 the eggs of the cenchris are red 

 like vermilion. In the egg itself there is a difference ; for 

 one end is pointed, the other round. The round end is pro- 

 duced first. The large, sharp eggs are males ; those which 

 are round and circular at the sharp end are females. 



3. They are matured by incubation. Some are hatched 

 spontaneously in the earth, as in Egypt, being buried in 

 dung ; and they say that in Syracuse a drunkard placed eggs 

 beneath his mat, and drank without ceasing until the eggs 

 were hatched ; and eggs placed in warm vessels have been 

 matured and hatched spontaneously. 



4. The seminal fluid of all birds is white, like that of 

 other animals ; and when they copulate the female receives 

 the male semen near the diaphragm. The egg at first appears 

 small and white, afterwards red and bloody ; as it grows it be- 

 comes quite ochreous and yellow ; when it becomes larger a 

 distinction is made, and the internal part becomes yellow, 

 the external white; and when it is perfected it is set at 

 liberty, and excluded just at the period when it is changing 

 from soft to hard. So that during exclusion it is not har- 



1 Cuculus canorus. 2 Numida Meleagris. 



3 Phasianus colchicus. 



