300 PROF. OWEN ON THE ANATOMY 



The remarkable concordance of the muscles of the rudimental wing in the Apteryx 

 with those in ordinary birds of flight, has been already pointed out. Nor is the corre- 

 spondence less remarkable in the muscles of the leg and foot, especially as manifested 

 in the condition of the ' perching muscle' (pectineus), in which it could hardly have been 

 anticipated. The strong flexors and extensors of the leg and toes are strictly adapted 

 to the exigencies of a bird which obtains probably most of its nourishment from the 

 earth by means of feet resembling those of the Gallinacea, and which owes its safety to 

 the speed with which it runs by means of legs which have almost the proportions of 

 those of the Struthious tribe ; and which, finally, is reported to seek concealment and to 

 incubate in subterraneous burrows. 



Female Organs of the Apteryx australis. 



The trunk of a specimen of this species, transmitted to me from New Zealand by 

 the lamented botanist Mr. Cunningham, having proved to be that of a female, enables 

 me to add to this anatomical monograph the description of the organs of generation 

 in that sex. These consisted of two ovaria and one oviduct. The right ovarium 

 (PI. XXXVI. a), was, as usual in Birds, in an atrophied state, and situated in front of the 

 corresponding suprarenal body, attached to that body and the adjoining trunk of the 

 vena cava. It was a small, flattened, minutely granular body, measuring eight lines by 

 five lines, and about one line in thickness. 



The left ovarium (PI. XXXVI. h) was in a state of full development, of the usual race- 

 mose structure, consisting principally of one enormous calyx (6), ripe for dehiscence, 

 containing the vitellus of an ovum, which measured three inches in length by two inches 

 in breadth, indicating an unusually large egg for the size of the bird. All the other 

 calyces were comparatively small, and the greater number of minute size. 



The oviduct commenced by the usual simple unfringed or entire slit-shaped aperture 

 (c), two inches in its long diameter: the tube soon contracted to a diameter of half an 

 inch, with longitudinally plicated walls, indicating its dilatability : it then expanded to 

 an inch diameter, and after slightly contracting, suddenly enlarged, to form the uterine 

 or shell-secreting part (rf) , which was nearly one inch and a half in diameter ; here the 

 muscular tunic is thicker, and the lining membrane presents a peculiar character, con- 

 sisting of transverse, linear, sub-parallel streaks, sending ofi" numerous short processes 

 at right angles, both streaks and processes being of a white colour, relieved by the 

 darker mucous membrane. A magnified portion of this structure is given at fig. 2. This 

 structure occupied nearly two inches of the uterine dilatation, which reassumed the 

 longitudinal plications about one inch before terminating in the uro-genital compartment 

 of the cloaca. The terminal outlet (e) is of a narrow elliptical form, with a tumid margin 

 covering a sphincteric arrangement of the muscular fibres. 



