and Classification oj Birds. 265 



Arrived at these generalizations, a suspicion is immediate- 

 ly cast on the reputed power of the ani, {Crotophaga), to imi- 

 tate sounds;* and on the reported song of the todies, {To- 

 dm) :f but we are tempted to ask why Mr. Swainson should 

 express surprise at the musical powers of the Cinnyrida?, at- 

 tested as they are by several observers of credit, on no other 

 ground than because he has thought fit to approximate them 

 to the songless group of humming-birds. % Examination of 

 the lower larynx of the two former genera, at once disproves 

 the assertions of numerous authors ; while, in the latter in- 

 stance, satisfactory confirmation is obtained. I have been in- 

 formed by observers of these birds in their native haunts, of 

 the fallacy of descriptions of the two former ; and Mr. Mac- 

 Leay relates that the loquacious boat-tailed grackle has been 

 repeatedly confounded with the ani. 



It is in the two groups which have been stated to possess 

 a complex vocal apparatus, conjointly with the diurnal Rap- 

 tores, that we find the highest cerebral developement in the 

 feathered class, accompanied by the maximum of intelligence, 

 or of sagacity as opposed to blind instinct ; while the reverse 

 extreme is likewise noticeable in the Insessores, in the in- 

 stances of the cuckoo, wherein the entire mass of brain bare- 

 ly exceeds in weight a single eye, and of the moth-hunter, 

 one eye of which considerably outweighs the brain ; — though, 

 in the latter case, the organ of vision happens to be of unu- 

 sual magnitude, the brain also being proportionally smaller 

 than in any other bird I know of ; in connexion with which 

 facts, it may be remarked, that the quality or attribute of do- 

 cility, or rather, perhaps, imitativeness, is peculiar among 

 the Insessores to the members of the three first-specified di- 

 visions ; for although there are many instances of insessorial 

 birds, not pertaining to these groups, which have been ren- 

 dered extremely tame and familiar, and which have become 

 considerably attached to persons whom they knew, distin- 

 guishing such very readily from strangers, yet I do not re- 

 member one wherein capacity for instruction has been exhi- 

 bited, which forcibly contrasts with the extreme docility of 

 the falcon, the parrots, and of the raven and its allies. It 

 should be borne in mind, however, that there are many spe- 

 cies, framed upon each of these three types of structure, which 

 are far from equalling the true falcons, the typical parrots, 

 and the crows, in mental superiority. 



I have already alluded to the secretion of a lacteal fluid by 



* Vide Regne Animal. f Vide Vieillot and others. 



| Vide Birds of Western Africa, Part i. 133. 



