INTRODUCTION, 131 
Before proceeding to consider the structure of Birds, it may 
be well first to cast a backward glance over the route we have 
come, and to once more take stock of the principal forms to 
which the reader’s attention has been called, as being so many 
specimens of different groups of Birds. 
Our object, as before said, has been to afford some help to 
the investigation and memory of the beginner in his attempt to 
obtain a mental grasp of the whole Class of Birds. For this 
purpose we have spoken of great groups arranged in a rough 
and ready, or popular, manner, as “ Scratchers” or ‘‘ Gallinaceous 
Birds,” as “ Cooers,” as “Swimmers or Natatory Birds,” as 
** Waders or Grallatorial Birds,” and as “ Runners or Cursorial 
Birds.” 
Amongst the many forms to which we have referred since 
speaking of the Emeu*—the last of our Cursorial Birds mentioned 
—are a certain number which have feet specially modified so as 
effectually to help them in climbing—two toes being turned one 
way, the two others being turned the opposite way. Amongst 
the Birds the feet of which are thus moditied, are the Wood- 
peckers, Wrynecks, Jacamars, Cuckoos, Barbets, Toucans, Tou- 
racous, Plantain-eaters, Parrots, and Trogons—the last named 
being specially exceptional in the arrangement of their toes. 
All these Birds, thus specially fitted for climbing, have been 
distinguished as ‘‘ Climbers ” or “ Scansorial Birds.” 
The Birds last noted by us—the Hawks, Falcons, Buzzards, 
Kites, Eagles, Ospreys, Vultures, and Owls—are all Birds of 
Prey or Rapine, and they are hence spoken of as “Raptorial 
Birds.” Those most like the Hawk, the generic name of which 
we saw was “ Accipiter,” are also distinguished by the epithet 
“¢ Accipitrine.” 
Almost all the rest of the Birds we have herein referred to 
(i.e. all since the Cursorial Birds, which are neither Scansorial 
nor Raptorial) are, however different in size, form, or appear- 
ance, frequently called Perching Birds, Perchers, or Insessores. 
From the name of their commonest species, the Sparrow, 
“ Passer,” they have also been called Passerine Birds or “ Pas- 
seres;” and most of them are still commonly so denominated. 
They constitute the great majority of the whole class of Birds. 
On account of their prodigious numbers it was long ago felt 
necessary to divide their members amongst subordinate but large 

* See ante, p. 67. 
