44 



KNOWLEDGE 



[Makch 2, 1891. 



Fig. 1. — The Bokes 

 OF THE Right Leg 

 OF the Giakt Moa. 

 About jij nat. size. 

 {After Owen.) 



the leg of a bird and that of a reptile, they are not well 

 suited to oui- present pui-pose. 



A bird's leg, then, as shown in Fig. 1, is composed 

 of four segments ; the upper short one corresponding to 

 the human thigh-bone, and the lowest 

 representing the toes, which are com- 

 posed of several small bones. Between 

 these two segments are the two long 

 and slender bones shown in the figiu-e. 

 The upper and longer of these two 

 corresponds with the human leg-bone, 

 plus the knuckle-bone welded on to its 

 lower end. The lower and shorter 

 bone, of which another example is 

 shown in Fig. 2, is a very remarkable 

 bone indeed, and may be conveniently 

 ca:lled the cannon-bone. It is reaUy 

 composed of three separate long bones, 

 of which the ends remain free at the 

 lower extremity and carry the toes, 

 and also of the lower part of the ankle 

 welded on to the upper end. The 

 middle long bone corresponds exactly 

 with the cannon-bone of a horse, 

 the nature of which has been explained 

 in the article on " Eudimeutal 

 Organs"; and the whole compound 

 bone would correspond with the meta- 

 tarsus of the extinct three-toed horse 

 known as the Hipparion, if its three 

 metatarsals were wielded together, and 

 these again with the bones of the lower half of the ankle. 

 It will, accordingly, be evident that a bird is an odd-toed 

 animal like a horse (that is to say, the toe representing 

 the middle one of the typical five is symmetrical in itself 

 and larger than either of the others), 

 having a cannon-bone, but no sepa- 

 rate ankle-bones ; the upper ankle- 

 bone having become welded on to 

 the leg-bone, and the lower ones 

 similarly united to the cannon-bone. 

 In these respects, therefore, a bird 

 is a very specialised kind of creature, 

 as departing widely from the original 

 type. With these necessary ana- 

 tomical explanations, we shall be in 

 a position to enter on the subject of 

 the extinct Giant Birds. 



The first of these extinct birds 

 brought to the notice of the scientific 

 world were the Moas of New Zea- 

 land, in which islands the largest 

 existing representatives of the group 

 the diminutive Kiwis. The original determina- 

 tion of the former existence of these giant birds affords, 

 uideed, an mteresting instance of the certainty of ana- 

 tomical deductions, when made with proper care and 

 suflicient knowledge. Thus, many vears ago a man 

 brought to Sir R. Owen the broken shaft of the thigh- 

 bone of some large animal, which he stated had been 

 obtained from New Zealand, where the natives beUeved 

 that similar bones were those of a large eade. The 

 specimen was a somewhat unpromismg one,%ut after 

 careful comparison the Professor confidently pronounced 

 that It belonged to an extinct bird considerably larger 

 than any ostrich, for which he proposed the name of 

 Dimniis. Other specimens soon after brought to this 

 country triumphantly estabhshed the correctness of this 

 bold identification, and showed that giant birds far sur- 



Fiii. 2. — Frost and 

 Back Views of the 

 Left Caxxon-bone of 

 A Partridge. 



are 



passing in size any pre\'iously known must have existed at 

 a comparatively recent date, and in extraordinary numbers 

 in New Zealand. In the swamps — especially the well- 

 known one of Glenmark, near Canterbury — these bones, 

 and in some cases nearly entire skeletons, are very abun- 

 dant ; wliile in caves there have been obtained not only 

 parts of skeletons with the skin still adhering to them, 

 but even well-preserved feathers, and broken egg-shells. 

 Although the JIaoris well know that these remains 

 belonged to gigantic birds, and give them a name of which 

 the word Moa is generally considered to be a corruption, 

 yet there is some difference of opinion as to whether tlieir 

 ancestors ever saw these birds in the flesh ; some autho- 

 rities considering that they were killed off by the race 

 which is believed to have inhabited New Zealand before 

 the advent of the Maoris. Still, in any case, Moas must 

 have existed up to a very late epoch ; and it is even said 

 that the " runs " made by them were visible on the sides 

 of the hLUs up to a few years ago, and may, indeed, stUl 

 be so. 



The leg-bone of a Moa may be at once known from 

 that of all living Giant Birds by the circumstance that on 

 the front surface of its lower end, immediately above the 

 knuckle-bone, there is a narrow bar of bone forming a 

 bridge over a small groove (this being indistinctly shown 

 in Fig. 1). In the Giant Moa, of which the leg is repre- 

 sented in Fig. 1, the leg-bone attains the enormous length 

 of one yard, and in an allied species from the South 

 Island its length is upwards of 39 inches. The cannon- 

 bone (as may be seen in the figure) is comparatively long 

 and slender, and is more than half the length of the leg- 

 bone. A skeleton of a smaller individual in the Natural 

 History Museum has an approximate height of 10| feet, 

 and we may thus conclude that the larger birds did not 

 stand less than 12 feet. There were other species of true 

 Moas, of about the dimensions of a large male ostrich, 

 although of stouter build ; and resembling the larger birds 

 in having only three toes to the feet, and not the slightest 

 trace of a wing. 



Alongside of these giants there w^ere, however, other 

 species of much smaller size, in which there were four 

 toes to each foot, and the cannon-bone was relatively 

 much shorter. Thus the Dwarf Moa, of which the 

 Natural History JIuseum possesses a complete skeleton, 

 was not more than three feet high, while Owen's Moa was 

 of still smaller dimensions. There were also other species 

 of this group nearly as large as an ostrich. 



Perhaps, however, the most remarkable of all these 

 bu-ds is the Elephant-footed ]\Ioa, which, although by no 

 means equal in height to the Giant Moa, was of much 

 more massive build. In this extraordinary bird the leg- 

 bone is much shorter and thicker than in the Giant Moa, 

 while the cannon-bone is so short and thick that it almost 

 loses the character of a " long bone." In one unusually 

 large example of the last-named bone, while the length is 

 only 9J inches, the width at the lower end is upwards of 

 6|. By the side of such a bone the cannon-bone of an 

 ox looks small and slender, and the effects of a kick from 

 such a leg can be better imagined than described. 



The total number of kinds of Moa inhabiting New 

 Zealand was probably at least fifteen, and, from the 

 enormous accumulations of their bones found in some 

 districts, we may assume that these creatures were ex- 

 tremely common, and probably went about in droves. 

 Nothing like this bird-faima is known in any other part 

 of the world ; and its exuberance may be probably ex- 

 plained by the absence of mammals from New Zealand, 

 so that when the ancestors of the Moas once reached these 

 islands they found a fr'ee field for unhmited development. 



