146 ME. W. K. PAEKER ON THE STEUCTUEE AND 



articulates with the superoccipital, this suture being short without and of great extent 

 within ; the lower angle of the parietal hides this suture on the outside. But one 

 of the most important relations of the prootic is that with the basisphenoid, viz. at its 

 antero-inferior edge (Plate XIII. fig. 2). The suture of the prootic with the basi- 

 occipital lies at an obtuse angle to that with the basisphenoid ; above this line of 

 suture, and in front of the groove in which the trigeminal nerve lies (Plate XIII. figs. 

 2 & 3), a knob-like mass of the prootic is jammed into a rough cup in the basisphenoid, 

 between the thick divided posterior clinoid bridge [p.cl.) and the outspread " posterior 

 wings " (p.r.p.). The antero-inferior part of the prootic within (Plate XIII. fig. 4) is 

 smooth, convexo-concave, the scooping being at the mid line and below, for the bone 

 thickens round the " internal meatus " (Plate XIII. fig. 4) ; external to this thickening 

 the prootic is hollowed, in continuity with the concave surface of the alisphenoid. 

 Between the meatus, with its thickened margin and its drilled fundus, is the deep well- 

 like recess for the lateral lobe of the cerebellum (Plate XIII. fig. 4) ; and in the back 

 of this mass, towards the top, is the epiotic (ep.). Here is seen the suture between the 

 prootic and superoccipital, this suture being interrupted by the intrusion of the inner 

 face of the epiotic. Down in the depths of this pit can be seen a right-angled smooth 

 facet of the exoccipital ; below the lower junction of the prootic with the superoccipital 

 comes the head of the opisthotic (inner) wedge (Plate XIII. fig. 4, op.) ; and the lower 

 margin of the superoccipital is viewed resting upon the prootic in front, the opisthotic 

 in the middle, and the exoccipital behind. 



This may be complex enough, but the heaviest part is to come ; and those who have 

 merely studied anatomy in the pleasing works of the transcendentalists, and who have 

 learned that both the basisphenoid and the presphenoid are found in the chondrified 

 sheath of the notochord, and that to be well seen in the bird they must be separated 

 by a saw, seeing that they are unhappily connate, will be rather staggered by the actual 

 bones figured in these Plates, and to be now described *. 



Undoubtedly the basisphenoid of the bird is the most remarkable of all known bones, 

 and a knowledge of its development is fundamental to the study, not only of the ornithic 

 skull, but, indeed, of all other skulls. For the skull alone, to say nothing of the cor- 

 poral part of each vertebrate microcosm, has on it the impression and obsignation of the 

 great universe itself; and " the edifice of this universe is, in its structure, to the human 

 intellect contemplating it, like a labyrinth; where from all sides there present them- 

 selves so many ambiguous pathways, such fallacious similitudes of things and their 



* " But this enslaved condition of the sciences is nought else than a thing bred from the audacity of the 

 few, and the sloth and pusillanimity of the rest of mankind. For as soon as any particular science has in parts 

 been somewhat diligently tilled and laboured, some one has usually arisen, confident in his talent, and accepted 

 and celebrated on account of the compondiousness of his method, who, in so far as regards appearances, has 

 established the art, but in reality has corrupted the labours of his predecessors. Yet what he has done is wont 

 to be well-pleasing to succeeding generations on account of the easy utility of his work, and their wearisome- 

 ness and impatience of renewed inquiry." — Bacon, Prolegomena to the ' Instauratio Magna.' 



