G8 MALDONADO. 



these two genera are witlely removed from each 

 other. Many theories, even phrenological theo- 

 ries, have been advanced to exjilain the origin of 

 the cuckoo laying its eggs in other birds' nests. 

 M. Prevost alone, I think, has thrown light by his 

 observations* on this puzzle : he finds that the fe- 

 male cuckoo, which, according to most observers, 

 lays at least fi-om four to six eggs, must pair with 

 the male each time after laying only one or two 

 eggs. Now, if the cuckoo was obliged to sit on 

 her own eggs, she would either have to sit on all 

 together, and therefore leave those first laid so 

 long that they probably would become addled, or 

 she would have to hatch separately each egg or 

 two eggs as soon as laid : but as the cuckoo stays 

 a shorter tiine in this country than any other mi- 

 gratory bird, she certainly would not have time 

 enough for the successive hatchings. Hence we 

 can perceive in the fact of the cuckoo pairing sev- 

 eral times, and laying her eggs at intervals, the 

 cause of her depositing her eggs in other birds' 

 nests, and leaving them to the care of foster-pa- 

 rents. I am strongly inclined to believe that this 

 view is con-ect, from having been independently 

 led (as we shall hereafter see) to an analogous con- 

 clusion with regard to the South American ostrich, 

 the females of which are parasitical, if I may so 

 express it, on each other ; each female laying sev- 

 eral eggs in the nests of several other feinales, and 

 the male ostrich undertaking all the cares of incu- 

 bation, like the strange foster-parents with the 

 cuckoo. 



I will mention only two other birds, which are 

 very common, and render themselves prominent 

 from their habits. The Saurophagus sulphuratus 



* Read before the Academy of Sciences in Paris. L'Institut, 

 1834, p. 418. 



