DEVELOPMENT OE THE SKULL IN THE BATRACHIA. 
665 
just reaches, and a little overlies the junction of these bones (fig. 1). The “ suborbital 
fenestra ” is here finished in front by the maxillary ; the cartilage is absorbed at that part. 
The only important change to he looked for in the debris of the branchial arches 
would be the ossification of the thyro-hyal bar (Plate 60. fig. 7, hr. 2, 3 ) ; this part had 
been removed in Professor Huxley’s specimen. 
Concluding Remarks. 
In the prosecution of this special kind of research I am under the necessity of keeping 
to the driest morphological details, making comparisons from time to time of like parts 
in diverse types. 
It was a good day for this work when Professor Huxley resumed his researches in the 
Amphibia (winter of 1873-74), for that gave rise to a discovery of the errors in my 
former paper on the Frog’s Skull. Finding him thus engaged, and receiving his criticism, 
I gladly took up the amphibian types again, working as much as possible in concert with 
him, and especially reexamining all those points on which we differed at that time. 
The result has been all but unanimity ; and my own mind is still open to further 
modification of views, when evidence of any unsafeness of deduction or of incorrectness 
of observation shall be forthcoming. 
Professor Huxley has acknowledged to me the extreme arduousness of this kind of 
work, and we both agree that the Amphibia, and the Anura or Batrachia especially, are 
the most instructive, albeit they present the knottiest problem of all the Yertebrata. 
At present I defer giving any special summary : in the beginning of the present paper 
I have thoroughly sifted my older work, and it need not be done twice over. Here it 
is seen that the Frogs differ in important things from the Toads ; the Toads that have 
a tongue from the “ aglossal ” types ; and that the two types of tongueless Toads differ 
from each other in many instructive particulars. 
Ready to follow this paper is one which will treat of the stages of the Bull-frog 
(Rana pipiens) and the Paradoxical Frog (Pseudis paradoxa) ; but to these I wish to add 
the Tree-frogs, the Bombinator Toads, and sundry other types of Batrachia, to say 
nothing of the Salamandrian or “ Urodelous ” Amphibia. 
In my former paper (p. 202) I spoke of the light that the Batrachian skull sheds on 
that of the Mammalia ; surely that assertion is not in the least belied by what is here 
written concerning the marsupial , gill-less young of the Surinam Toad. 
I am not unaware that this kind of labour may seem to be the mere heaping up of 
details ; to speculative minds, certainties and systems are demanded from the first ; 
such certainties and such systems end in doubt and scientific confusion. 
But I believe that when certainty has been painfully attained (although it be through 
much doubt and long-continued research), then a system will grow spontaneously, as a 
real living thing, and not as a mere human fantasy. 
All the confusion arising from my mistaken view of the early coalescence of the upper 
part of the hyoid with the mandibular pier is now gone, and the cartilage which was 
mdccclxxvi. 4 z 
