8434 Notices of New Books. 



singularly and apparently awkwardly-shaped wings ? Generally the 

 primaries and secondaries are of a sombre and uniform hue, while the 

 shoulders or wing-coverts in most instances are of the same colour as 

 the other parts of the body. There are, however, a few, but a very 

 few, exceptions to the rule, and I may mention the Eulampis jugularis 

 and Pterophanes Temminckii as instances in point ; both these birds 

 have luminous wings, and must form very striking objects during flight, 

 and, as I believe colour is seldom given without the intention of its 

 being exhibited, there is doubtless something peculiar in the economy 

 of these birds. The primaries and secondaries are in some instances 

 stiff and rigid, while in others they are soft and yielding ; some are 

 broad, others narrow ; they are always the same in number, and the 

 first quill is constantly the longest, except in Polytmus cephalater, 

 where the second exceeds the first in length." 



The tail, so often called the " bird's rudder," must necessarily be 

 considered in connection with its wings the undoubted propellers of 

 the bird's course through the air. 



The Humming Bird's Tail. — " Connected intimately with the mode 

 of flight is the form and structure of the tail, and in no group of birds 

 is this organ more varied ; in some species it is four times the length 

 of the body, in others it is so extremely short as to be entirely hidden 

 by the coverts. Every humming bird, however, has ten tail-feathers 

 and no more. I am aware that this number is not apparent in some 

 of the smaller fork-tailed species, the two centre feathers being so 

 exceedingly minute as to be almost obsolete ; but if a careful exami- 

 nation be made that number will be found. The tail appears to be, 

 and doubtless is, a very important organ in all the aerial movements 

 of the Trochilidae, and accordingly we find very great variations in its 

 form among the many different genera of which the family is composed. 

 In Cometes and Lesbia the forked character is carried to its maximum, 

 while its minimum is seen in Calothorax, Acestrura and the allied 

 groups. The tails of all the members of the two former and many 

 other genera are of this form, while in others it is only seen in a single 

 species of a group, all the other members of which have rounded, 

 square or cuneate tails. Next to this we may notice the species with 

 feathers terminating in spatules, such as Loddigesia, Spathura, &c. 

 I was informed by the late Mr. Dyson that the flight of these birds 

 presents a marked difference from that of other humming birds, and 

 that their appearance in the air is most singular, the tail being not 

 only constantly opened and shut, but the spatules always in motion, 

 particularly when the bird is poising over a flower ; and if this be 



