172 
ME. W. K. PAEKEE ON THE STEUCTTTEE AND 
fig. 5, and Plate X. figs. 1 & 2, h.br.), which have now become solid bony rays, soft at 
the end and diverging at nearly a right angle to each other, so as to enclose the larynx 
(Lx.) ; and thus they form a pair of true “ cornua majora ossis hyoidei.” 
Ninth Stage. — Frogs of the first autumn. 
In the course of the first summer the Frog more than doubles its bulk ; and these 
more developed individuals present several important changes. As the head at this stage 
is still, when partly macerated, a small, flat, and compressible object, it can be mounted 
in glycerine after being treated with caustic soda, and thus have all its parts brought into 
view under different magnifying powers ; the figures (Plate VIII. figs. 7, 7“, 8, S“) are 
taken from such a preparation. 
The premaxillaries (figs. 7, 8, p.mx.) are now well developed in both their processes, 
nasal above and palatine below, and have become dentigerous. 
The “ septo-maxillary” (fig. 7, s.mx) is now better seen as a notched and grooved plate 
of bone lying on the floor of the nostril. The maxillaries ( mx .) are now dentigerous, and 
their ascending facial plate and zygomatic process are now much advanced ; the latter, 
however, does not yet reach the quadrato-jugal process of the quadrate (q.). 
The nasals (n.) are much altered in shape : they have retained their curve ; but the upper 
part is now a broad semioval shell, sending down the lower as a mere spur overlying 
the palatal suspensorium. 
The “coronal suture” is still visible between the frontals and parietals (f, p.); 
and the former are making a more perfect roof to the front end of the great fonta- 
nelle (fo.). 
“ Below, the vomers (fig. 8, v.) have acquired their trifoliate shape ; the teeth easily peel 
away from their stalk or posterior process ; the internal nostril lies between and external 
to the second and third lobes ; the first lobe grows forwards and nearly touches the pre- 
maxillary. The “ parasphenoid” (fig. 8 ,pa.s.) has become much denser ; it is also broader 
in front. Laterally, we see that the temporal bone (figs. 7 & 7", s.t., sq.) has become 
typical; for now the supratemporal longitudinal bar (s.t.) is well developed, clamping 
the extended periotic capsule behind, and running forwards into the postorbital region. 
Its descending bar is now very characteristic, being stout and expanded below as a strong 
suspensorial splint. The quadrate ectosteal plate (q.), with its long quadrato-jugal pro- 
cess, is noAv more easily to be understood; for it has fairly grafted itself upon the qua- 
drate cartilage, which the mere “quadrato-jugal” never does. 
On the under or inner side (fig. 8) we see a new bony bar ; it is /-shaped, delicate 
and narrow, and is immediately applied to the suspensorial part of the palatal carti- 
lage ; this is the Batrachian counterpart of the perfect bony sheath of the Fish’s palatal ; 
it does not yet touch the pterygoid. This latter ectosteal plate (pg.) is now well deve- 
loped, although it does not quite embrace the cartilaginous rod (fig. 7“ & 8“, p.g.). Its 
posterior descending process is very Reptilian ; its metapterygoid process (m.p.g.) is now 
a mere spur of bone binding the front of the “ infrahyomandibular,” a bone which 
