likeness of the owls to the hawks is to be distrusted, as merely due to a similar mode of life, and therefore to the development of certain structures which are in direct relation to that mode of life, how about the superficial likeness of the owls to the goatsuckers, which is almost as well marked as to the hawks? In Australia and other parts of the East there are two genera of goatsuckers which have received the names of Podargus and Batrachostomus. These birds are wonderfully like owls. They have the same brown-and-grey and soft plumage; their flight is equally noiseless--and, altogether, anyone who saw the living Cuvier’s Podargus recently on view at the Zoological Gardens might well be pardoned for thinking it an owl. The fact is that we must be careful not to be prejudiced in any direction. Superficial similarities may or may not go with real likeness. Speaking generally, one should be disposed to lay greatest stress upon characters which have no obvious relation to mode of life as likely to be of the most use in indicating blood relationship. It is easier, however, to lay down general principles of this kind than to apply them to birds. As has been already mentioned, birds are so uniform in anatomy that in such characters as brain, lungs, and other internal organs which are not so directly under the immediate influence of their surroundings, there is but little difference. Such characters afford no help to the systematist. We are obliged, therefore, to rely upon other and really less important points.