ANALOGIES OF GROUPS. 2907 
division of another. If the group under comparison be 
natural, all the other analogies of the types will be ap- 
parent. Thus, if we wished to test the tribe of Te- 
nuirostres with the order of the Jnsessores, and the 
orders of the class Aves, the three series would stand 
thus :— 
Tenuirostres. Insessores. Aves. 
1. Typical. Trochilide., Conirostres. INSESSORES. 
2. Sub-typical. Cinnyride. Dentirostres. RAPTORES. 
Meliphagide., Scansores. RASORES. 
~ 3. Aberrant. } Paradiside. Tenuirostres. GRALLATORES, ° 
Promeropide.  Fissirostres. NATATORES. 
For although the T'rochilide are pre-eminently the 
tenuirostral type of the Jnsessores, they are not to be 
so denominated in their own circle. This, indeed, will 
be abundantly evident, when we consider that this very 
pre-eminence places them at the head of their own 
tribe, precisely on the same principle that the Insessores 
stand in the same relative situation among the orders 
of the whole class. In further proof of this mode of 
judging, we find that the climbing Meliphagide come 
opposite to the Scansores, and the syndactyle-footed 
Promeropide represent the Fissirostres and the web- 
footed Natatores. None of these beautiful relations 
would be apparent, if the series of the Tenwirostres 
had been so placed that the Trochilidie stood parallel to 
the tenuirostral division, in the column of the Jnses- 
sores: it seems, in fact, absolutely essential to reduce 
every group to its primary divisions, before the analogies 
of the group itself can be properly verified. 
(361.) Against the above opinion, however, there 
seems to be a serious objection ; inasmuch as that, upon 
looking to the last table, it will be perceived that the 
tribes of the Znsessores follow each other, in the column, 
precisely in the same order as they do in nature, but in 
that of the orders of birds (Aves), the series is irregular, 
because, naturally, the Natatores, and not the Rasores, 
come after the Raptores ; the question therefore is, In 
what manner can this. be accounted for? does it result 
from placing the Trochilide as representatives of the 
Conirostres, rather than of the Tenuirostres ? or is 
