192 Observations on the 



of the highest rank, they arc adopted implicitly by those who 

 have not leisure or inclination to think for themselves, and are 

 hailed with triumph by all who contend for the ancient and 

 limited landmarks of the science. It is necessary to give these 

 arguments a distinct examination. Were they allowed to pass 

 current, the discoveries that every day take place of the opera- 

 tions of nature, and of the principles that prevail throughout her 

 works, as well as the inferences that result from these discoveries, 

 would be rendered totally abortive and unprofitable. 



M. Temminck, whose name is deservedly high in the ranks of 

 Ornithology, has rendered himself conspicuous by his opposition 

 to the admission of the greater number of genera established by 

 his contemporary naturalists. The main objection which he urges 

 against them is, that, however distinct some species in the new 

 genus may be from the generality of the group from which they 

 have been separated, other species are so united to it by a gradual 

 approximation as to render it impossible to draw a line of distinc- 

 tion between the new group and the old. lie lays particular 

 stress on the passage that thus takes place between these con- 

 terminous groups, and in every instance he draws the conclusion 

 that the new genus must fall, where such an intervening passage 

 exists. This doctrine is so particular a favourite with him, that 

 he dwells upon it on every opportunity, in almost every page of 

 his works, in every succeeding volume that is the fruit of his 

 valuable labours.* It is the knowledge of these intervening gra- 



* A few examples, taken almost at random, from the " Manuel d'Orni- 

 tliologie," will sufficiently explain the Professor's views on this subject. " Le 

 genre strix, si bien characterise — a aussi du etre subdivise recemment en un 

 grand nonibre dc genres nouveaux, — les especes etrangeres rendent ces divisions 

 absolument nullcs, elles presentent un passage sans intervalle assignable, et 

 n'oti'rent poui tout moyen de classification methodique, qu'unc grande serie 

 d'especes." — p. 79. " Daudin a propose les genres Icterus et Cassicus pour 

 ces oiscaux Americains: M. Vieillot en ajoute encore d'autres, mais les limiles 

 de ces genres nombreux ne peuvent itre fixees avec precision ; le passage dcs uns 

 mi d mitres a lieu par nuances presque imperceptibles. Je propose consequemment 

 de reunir tous ces oiseaux d'Amerique dans ie seul genre Icterus.''^ — p. 128. 

 ■'Les methodistes oatessaye de classer ces oiseaux [les Gros-becs j en plusieurs 



genres, . Cost vainement qu'on inventerait encore double et triple de 



iioms noMVcaux poiii' former des groupes birictemeiil mclhodi<iues. — J'ai mis 



