933 



STUUTHIONID^l 



STRUTUIOXIDJi 



Strongly contrasted with the flattened sternum and the dwindled 

 autrrior extremities are the strongly developed pelvis and posterior 

 limb* of the Slnikimida. The pelvis of the ostrich bean some 

 resemblance to that of the extinct quadrupedal Mylodon, of which 

 there is a noble skeleton in the Museum of the Royal College of 

 Snrxeons. In this part of the osseous system we have ample fulcra 

 for those powerful muscles which render the larger Struthious Birds 

 swifter than the swiftest. The iliac bones of Apteryi resemble those 

 of the rest of the tribe in siz* and shape, and are four inches and three 

 lines in length. There is a slight anterior concavity on the outer 

 surface, and this concavity passes into a convexity posteriorly, the two 

 surfaces, not being separated by the transverse elevation which exists 

 above the acetabulum in the four large Struthionitlir. Between the 

 posterior extremity of the ilia and tlio first three caudal vertebrae, a 

 distinct epiphyseal piece of bone is wedged in. The ischium extends 

 backwards parallel with the sacrum, in the form of a thin plate of 

 bone, which slightly expands to its free and truncated extremity. 

 The pubic element is a slender bony style, connected by ligament 

 to the end of the ischium, but attached by bone at its acetabular 

 extremity only. A short pointed process extends from the anterior 

 margin of the origin of the pubis. In comparing the pelvis of Aplery.c 

 with that of the large Struthious Birds, Professor Owen observes that 

 the iacbia do not meet below the sacrum, as in the Kliea, but are more 

 distant from that and the iliac bones than in any of the Struthionidcc ; 

 the pubic bones, he remarks, are not joined together at their distal 

 extremities, as in the Ostrich ; nor are the extremities of the iachia 

 anchvloeed to the superincumbent ilia, as in the Cassowary. It is the 

 Emeu, he adds, that comes nearest to the Apleryx in the structure of 

 the pelvis, but it also differs in the complete bony boundary of the 

 foramen, which transmits the tendon of the obturator internus, and 

 which is completed posteriorly by ligament in Apttryx. The aceta- 

 bulum, he observes, communicates, as usual, by a wide opening with 

 the pelvis, and a surface covered with a cushion of thick cartilage is 

 continued from its posterior and upper part. 



The great length of leg in the Strttthionidte is produced, as in the 

 true wading-birds, by the tibia and common bone of the tarsus and 

 metatarsus ; for the femur is comparatively of short dimensions. 



The fibrous capsule of the hip-joint of Apleryx is very strong ; the 

 nynovial membrane is reflected from it upon the upper margin of the 

 trochanter and upper part of the short neck of the femur, as well as 

 upon the ligameutous bridge, continued from tho upper and extended 

 margin of the acetabulum to its anterior part. The very large liga- 

 mentum teres is short, and consists of an infundibular process of 

 synovia! membrane, reflected from the circumference of the acetabular 

 perforation to that of the depression on the head of the femur : this 

 synovia! sheath incloses two distinct ligaments, which are twisted about 

 each other like the crucial ligameuta of the knee-joint One of the 

 ligameutous bands passes from the upper margin of the acetabular 

 perforation to the lower edge of the femoral depression. 



The femur, tibia, patella, fibula, and other parts of the osseous 

 system of the legs of these birds are not leas characteristic of their 

 habits. 



The number of the toes varies in these birds. In the Ostrich the 

 number of toes is two only ; the Cassowary and Emeu have each 

 three. The Apteryx has a fourth. In the Aptcryx the number of 

 phalanges of the three greater toes follows the ordinary law; 

 the inner toe having three, the middle four, and the outermost five 



; i. . ;: _ . 



The crop in the Slrulhionidte is of great size. The bulbus glandu- 

 losus orproventriculus is situated before the entrance of the oesophagus 

 into the proper stomach, and is so large and so modified in form in 

 some of the species, the Ostrich for example, as to give it the appear- 

 ance of a second stomach ; indeed Valisuieri, in his ' Anatomy of the 

 Ostrich,' calls it the first stomach. Mr. Lawrence found the oesopha- 

 gus of an ostrich which he dissected dilated into an immense bug 

 capable of holding several pints of water, and five or MX times larger 

 than the gizzard itself, which was placed on the right and anterior 

 part of this dilatation. The glands did not surround the tube, so that, 

 Mr. Lawrence observe*, the term 'zone' would be hero inapplicable. 

 They formed, he tells us, a long but narrow baud, commencing at the 

 termination of the oesophagus, and running along the front of the 

 bag towards the gizzard. This band measured about twelve inches 

 in length and not more than three inches at its greatest breadth. 

 The size of thu individual glands varied : they were largest in the 

 middle, and decreased towards either margin of the band. Some of 

 them equalled a large pea, and their openings were in proportion. 

 They were arranged in close apposition to each other, and the inner 

 surface of the pouch was covered by a continuation of thu iuseuoiblo 

 lining of the gizzard, which separated very easily from the surface. 

 The cteca in the ostrich are characterised by a remarkable spiral vulve, 

 and the villi in its small iutcstiue are ratner flat thin lamina) than 

 villi ; but they are at the same time long and numerous, presenting a 

 very el- g*at structure. The large intestine of the ostrich presents a 

 remarkable deviation from the structure usually seen in birds ; for 

 the surface of that intestiue in in them generally uniform on its surface, 

 whereas in the Ostrich the large intestines, wbiuh are very long, have 

 numerous transverse folds, like the valvuhc conuiveutes of man. 



In the Museum of the College of Surgeons in London is a series of 



preparations admirably illustrative of tho internal anatomy of the 

 StruthiOHicUe. 



The tongue of the Apttryx is short; but short aa it Is, it is more 

 developed than in other Struthious Birds. The lining membrane of 

 the pharynx, behind the glottis, forms two elongate, square-shaped, 

 smooth, thick, and apparently glandular folds or processes, the obtuse 

 free margins of which project backwards like lappels into the pharynx ; 

 beyond which the lining membrane is produced into close-set, narrow, 

 somewhat wavy, longitudinal folds; the oesophagus is continued 

 through the thorax and diaphragm to the proveutriculus without 

 forming any partial dilatation or crop. The proventriculus is a 

 narrow elongated cylindrical cavity in tho axis of the oesophagus, of 

 which it is an immediate continuation. The gastric glands, narrow 

 elongated follicles, are developed around its whole circumference, and 

 are closely packed together ; they are mostly bilobed, but sometimes 

 more subdivided at their casual or outer extremities. The longitudinal 

 ruga) of the lining membrane gradually subside at the entry of the 

 proventriculus, where they run into each other, and so form a gem ml 

 reticulate surface, in the meshes of which the orifices of these glands 

 are situated. The epithelium lining the glandular part of the stomach 

 is gradually condensed towards its lower port into a cuticle, which, 

 as it passes into the muscular compartment, assumes a brown colour 

 and a callous hardness, and forms a stratum about one-third of a line 

 thick. In the Cassowary and Emeu, observes Professor Owen in con- 

 tinuation, the proveutriculus is marked off from the stomach by a 

 circular strip of epithelium, whiter and thinner than the rest, from 

 one to two lines in width, as is well shown in Sir Everard Home's 

 Comparative Anatomy ' (pL li., Hi.) In this structure the Aptcryx, 

 though it resembles these species in the arrangement of the gastric 

 glands, does not participate. Its muscular stomach does not present 

 the characteristic sub-compressed shape of a gizzard ; but in its regular 

 oval rounded form resembles the membranous stomach of carnivorous 

 birds. It is small for the size of the bird iu its contracted state, but 

 when distended with food Professor Owen found that it measured two 

 inches and a half in length, and two inches across at the widest parts. 

 The muscular fibres are not digastric and lateral, as in the true gizzard ; 

 but, instead of being arranged iu well-defined masses, radiate from two 

 tendinous oval centres, measuring about two-thirds of an inch in the 

 longest diameter. The pyloric passage is narrow, leading from tho 

 left side of the muscular stomach into the duodenum. A transverse 

 croscentic ridge of the lining membrane defends the pylorus, but 

 there is no distinct sphincter. The cuticle is continued into the 

 duodenum about three lines beyond the pylorus, but the Professor 

 found no dilatation of this part constituting a pyloric pouch, as in the 

 Emeu and Ostrich. In one Apteryx there was a very short oeouui, 

 the remnant of the ductus vitcllo-intestiualis, attached to about the 

 middle of the small intestine ; and from, the same relative position of 

 the intestinal tube in a small female specimen there extended an 

 obliterated duct three lines long, which expanded into a still persistent 

 sub-globular vitelline sac, about an inch in diameter, but collapsed, 

 and with wrinkled parietes. Iu a large male the intestinal canal 

 measured four feet, independently of the caoca, each six inches in 

 length : the rectum was four inches long. The lining membrane of 

 the rectum, which is beset with minute short villi or points, together 

 with glaudultn bolitiriic, that become numerous and Urge ut the 

 terminal half of the rectum, is thrown, when it is contracted, into 

 longitudinal folds ; but there is no trace of thu transverse or spiral 

 valvulie conuiventeg, characterising the aoea and rectum of the Ostrich 

 and Jt/tca; and in this respect the Aptcryx resembles the Cassowary 

 and Emeu. The liver presented nothing extraordinary. In two of 

 the specimens there wa a gall-bladder, as iu tho Emeu and Cassowary ; 

 in the third it was wanting, as is usually the cose in the Rkea and 

 Ostrich. In tho Apteryx without a gall-bladder there were two long 

 ducts terminating in thu sarnu part of the duodenum. The pancreas 

 consisted, as usual, of two elongated subtrihedral lobes; and the 

 spleen was about the size and form of a hazel-nut. 



Iu the preparations iu the College of Surgeons the peculiarities of 

 the circulating and respiratory systems of these birds are well dis- 

 played. Tho Apteryx possesses a complete and well-developed 

 diaphragm. 



Professor Owen, after adverting to the long recognised existence of 

 a diaphragm in a rudirnental condition in birds, and Hunter's beauti- 

 ful figure of tbe costal portion of that of the Ostrich (' Cat Mus. 

 Colt Chir.,' vol. it, pL xxvi., ' Phyaiol. .Series '), observes that in this, 

 as well as in the other large .Struthious liirds, there is also a pars 

 vertebralis, or analogue of the lesser muscle of the diaphragm, which 

 rises by two tendinous crura from the last dorsal vertebra, and in the 

 Emeu, by a double origin on each aide. Nevertheless, he remarks, 

 tbeir diaphragm is incomplete ; first, by reason of an arrest of its 

 centripetal development, which leaves a permanent defect of union in 

 the mesial plane ; and, secondly, by the large perforations for the 

 abdominal air-cells. 



Professor Owen found the mechanism of respiration iu the Apteryx 

 essentially the same as iu other birds, and he states that a more 

 muscular diaphragm than it possesses would be unnecessary as a part 

 of the mechanism. As in the Mammalia, the abdominal surface of 

 the diaphragm is principally in contact with the liver, spleen, and 

 stomach ; but itj thoracic surface does not support the heart, and it 



