AFFINITY OF TARDIVOLA AND PITYLUS. 115 
wonder, then, that some of our best writers, who seem 
to be acquainted with one or two of the typical ex- 
amples of Tardivola, should place it as a genus, in a 
totally different family. ‘To illustrate this extraordi- 
nary union of two subgenera (apparently so widely 
separated by characters which are usually considered 
indications of higher divisions), we subjoin the outlines 
163 
of the intervening gradations in the form of the bill 
just alluded to, and which will bear us out in the be- 
lief, that, whatever uncertainty hangs over other parts 
of our arrangement of the tanagers, the proximity of 
Tardivola to Pitylus is beyond dispute. 
(130.) This foregoing affinity being admitted, we 
are next to inquire into the cause why such a remark- 
able variation in the bill should occur in species so 
closely united. Now, it should first be stated, that 
nearly the whole of the seed-eating birds of Tropical 
America are composed of the tanagers, which, in those 
regions, supply the place of the other finches, so abund- 
ant in all partsof Europe. The seeds and hard berries, 
however, found in our cold and temperate climates, 
are very few indeed, when compared to the innumer- 
able variety produced in the vast forests of the New 
World, whether we regard the variety of the species, or 
the different degrees of hardness they possess. Now, 
as these small and hard fruits are the appointed food of 
the tanagers, (for the parrots chiefly subsist upon the 
larger nuts,) it follows, that an equal diversity of 
strength should be found in the bill; that organ, in 
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