Certain members of the Plover-tribe, and certain Anserine birds, have developed spurs of a very formidable character on the wings. Among the Plover-tribe the best example of such armoured species is the Egyptian Spur-winged Plover (_Hoplopterus_). This bird, after the fashion of its unarmoured relatives, such as the Common Lapwing, fights by turning suddenly in the air and striking with the wings. In the case of the formidably armed Egyptian bird the result is often fatal; but with our Lapwing a fatal result is rare, since but slightly swollen knobs take the place of spurs. In Hoplopterus and in the Jacana this spur arises from the base of the thumb, but in the Spur-winged Goose (_Plectropterus_) it is borne by one of the wrist bones (the radial) while in the aberrant Geese-like birds (_Palamedea_ and _Chauna_) there are two spurs on each wring, one at each end of the metacarpus. That these weapons have come into being in response to need seems a very natural conclusion, but it is one which presents many difficulties when more closely examined. The wing spurs, differing widely in their nature as they do, in one case borne on a carpal bone, in others on the metacarpus, seem rather to owe their origin to fortuitous variations which have become, so to speak, adopted by selection, than to a response to the oft-repeated stimuli incidental to fighting. The latter explanation is Lamarckian and to-day finds favour with but few. The stimulus theory seems to be effectually discounted by the existence of the spurs on the legs of gallinaceous birds. That these owe their origin to impacts, or blows, seems more than doubtful: and one can hardly see how they could have served any useful purpose until they had attained a sufficient length to serve as weapons. Even if we suppose that the spurs of, say, the Jungle-fowl or the Francolin have been derived from tuberosities such as are found on the legs of the French Partridge (_Caccabis rufa_), we should still lack evidence that the use of the legs in fighting caused the origin of the tuberosities.