52 



existence ; they compared the various caterpillars \vith tlie butterflies 

 which are produced from them, traced with indefatigable industry 

 the plan of nature in these animals, and discovered the resemblance 

 ■which was invariably presen'ed in the structure of species related to 

 each other in afBnity, in the diiferent stages of their existence." 



With these examples in view, I have been induced to consider the 

 egg of a bird as one stage or condition in the life of the animal : 



That the colour and raarkings we find deposited on the external 

 surface of the shell afford indications by which classification may be 

 assisted : 



That the eggs of congeneįic species ^vill resemble each other in 

 colour and markings, "\vhatever may be the geographical locality in 

 which such species are found. 



Mr. He\vitson, in the introduction to his work containing excellent 

 delineations of the eggs of British birds, observes, that " much useful 

 and highly interesting information might be gained tovvards the clas- 

 sification of birds, by paying some attention to their eggs ; and it is 

 gratifying to find, in thus regarding them, that, with the exception 

 of a few instances, vvere we to take the eggs of our British birds as 

 our only guide, \\,e should arrive at the best and most approved ar- 

 rangement of the diflferent genera." 



I am aware that exceptions and discrepancies may be pointed out. 

 The colour deposited on the egg-shells is an animal matter, depend- 

 ent on the health of the bird. Fear or confinement acting consti- 

 tutionally upon the organs of secretion are kno\vn to affect this 

 colouring-matter. 



The greatest amount of variation is found to occur among the 

 Lm-ida. 



With these preliminary remarks, I proceed to the description of a 

 coUection of eggs of some of the birds of Chile, obtained by Mr. 

 Bridges, and exhibited here by Mr. Cuming. 



Cathartes lota of Molina ; Chilian name lott. — The egg of this 

 Vulture measures 2 in. -^ in length, and 1 in. ^ in breadth : the 

 shape is rather peculiar, being broadest at the centre and tapering 

 gradually in both directions, so as to become pointed at both ends. 

 The ground colour is white, slightly tinged \vith red ; blotched with 

 pale red ; spotted and speckled with dark brownisli red. 



Httliaetus agnia, Temminck ; Aguila of the Spanish ; Caląuin of the 

 Indians. — The egg is 2 in. įi in length by 2 in. -^ in breadth ; 

 eiliptic ; white, with a few spots of dark red and numerous spots and 

 speckles of pale red. 



Polyborus Brasiliensis, Swainson ; Chilian name Traro and Taro. 

 — The Gįg of this bird is 2 in. y^ in length by 2 in. in breadth ; 

 blotched, spotted and speckled with dark red, on a ground of reddish 

 white. This egg, in its colour and markings, resembles those of our 

 British Osprej-. 



Milvayo pezoporos, Meyen ; Chilian name Tiiicue. — Tlie egg mea- 

 sures 1 in. ^ by 1 in. ^^^ ; white, tinged with red; blotched, spot- 

 ted and speckled with dark brownish red. 



