INTRODUCTION. 
47 
The great majority of the order are of compara- 
tively small size. 
Amidst this number of beings to be charac- 
terized, there has been unquestionably much 
difficulty, and considerable difference in the 
opinions of our systematists. The most of whom 
have considered what are placed as the subordi- 
nate divisions by the latest writers in a higher 
place, and have thus made their systems to con- 
sist of a much greater number of primary divi- 
sions, although, when the whole was analyzed, the 
discrepancies consisted more in the comparative 
value of the different parts, than in the points or 
boundaries within which each was contained. 
In the Systema Naturae, the orders are six in 
number, and correspond nearly with those at 
present advocated, the piece and passeres only 
being thrown together in the group we have now 
under consideration. In the Regne Animal, the 
orders are also six, the incessores of moderns 
being there still divided, though the separation is 
differently effected, the scansores (grimpeurs) 
being kept by themselves. By Illiger we have 
seven orders proposed, occasioned by the division 
of the grallatores, as well as the incessores, and 
in most of the systems where the number of 
primary divisions run between five and seven, or 
eight, it will be seen to be caused by the splitting 
of these two orders. When they extend beyond 
that number, as in the system of Temminck, 
composed of sixteen orders, and of others having 
even more, we have only a still farther separation 
