. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. PELVIS. 167 marked Uio-iscJdal angle in the reverse direc- tion to that of Mammals generally, i. e. with the retiring sides anterior (see Jig. 107.). The pubes of birds are generally long, slender, rib-like, and divergent, and are com- posed of a single curved branch (jj), having no angle, and never forming a true interpubic symphysis, though, in the Ostrich and Falco Fulvus, they are closely approximated at their posterior extremity, and form a sort of sym- physis. The ilio-pubic angle is very large, from 155° to 160°,
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. PELVIS. 167 marked Uio-iscJdal angle in the reverse direc- tion to that of Mammals generally, i. e. with the retiring sides anterior (see Jig. 107.). The pubes of birds are generally long, slender, rib-like, and divergent, and are com- posed of a single curved branch (jj), having no angle, and never forming a true interpubic symphysis, though, in the Ostrich and Falco Fulvus, they are closely approximated at their posterior extremity, and form a sort of sym- physis. The ilio-pubic angle is very large, from 155° to 160°, except in the birds of prey above alluded to ; and the pubes and ischia are generally almost parallel. Sometimes the posterior extremities of the pubes and ischia unite to form complete elongated obturator foramina ; and they may be united also near their anterior extremities, forming a lesser an- terior division of the foramina, as in the Cur- sores (sec Jig. 106. X:). Very often, the boun- daries of the obturator openings are incom- plete from the failure of this junction, and the foramina are wanting altogether ; or the an- terior union and foramina only may be present, as in the Duck (fig. 10-i. ?•), from deficiency of the pubes posteriorly, or their entire approxi- mation to the ischia. The pelvic cavity is in- creased in size posteriorly, by the divergence of the pubes and ischia, and is capable of great enlargement by the yielding of their unfixed extremities. The ilio-pectineal emi- nence is generally present, and often large in size, constituting a spinous process (</). The acetcibida (i) are perforated and placed almost close to the borders of the sacrum, and generally much anterior to the centre of the whole pelvic length, that the points of support may be nearer the centre of gravity. The bird's pelvis thus constitutes a firm, compact, immobile, box-like structure, de- ficient interiorly, affording a large and firm hold, by the elongated and strong ischia, f
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