116 MR. W. K. PARKER ON THE STRUCTURE AND 
hind part of the septum is marked with hills and hollows that correspond with the 
folds of the middle turbinal. 
SUMMARY AND CONCLUSION. 
In the present state of my research I can make but little use of comparisons, and 
draw very few deductions. Most of the work already done is still in the form of 
figures, with no written descriptions, and that is only about a fifth of the work laid 
out for me in the Mammalian Class. 
Nevertheless Iam much mistaken if the knowledge already obtained in this Order 
of the Edentata, alone, is not of considerable value ; the living types composing it are 
so far removed from each other by specialization that they, evidently—Family after 
Family—represent large groups of forms that must have existed in the past. 
As placental Mammalia, these types come, of necessity, into Professor Huxtry’s 
highest group—the “ Eutheria ;” and yet in both the skull and the other parts of the 
organization worked out by me, namely, the shoulder-girdle and sternwm, they come 
nearer at times to the Prototheria than the Marsupials themselves—that middle 
group, the Metatheria. 
Therefore it occurs to me, and the author whose terms I have just used will, I be- 
lieve, agree with me in this view, namely, that these Edentata are the direct children 
of the Prototheria. That they passed through a Metatherian stage is a thing not to 
be controverted, but I believe that it was not, in most cases at least, utilized—it was 
an abbreviated prenatal stage ; they lost their Marsupial bones and never acquired 
any Marsupial modification of their abdominal skin. A great satisfaction now arises 
to me from the fact that my very narrow line of research brings me to the reiteration 
of Professor FLoweEr’s views of the Edentata, znte se. 
The Old World types are sharply divided from those of the New World ; but types 
so ditferent in appearance and habits as the Sloth and the Ant-bear can be shown by 
embryology, as well as by their general anatomical structure, to be, in reality, closely 
related. Adaptive modification has done its utmost in these two cases; but it has 
only masked, it has not destroyed, the essential fundamental conformity of these two 
grotesque and aberrant types of Mammals. 
I need not repeat here what I said in the Introduction as to my change of views 
since the publication of my paper on the Pig’s skull (Phil. Trans., 1874, Plates 
28-37), as to the general homology of the “ossicula audittis.” The researches of 
Banrour, SALENSKY, and FrAsER have caused me to think over this question again, 
and to doubt the conclusion that Professor Huxtuey first, and I afterwards, had come 
to on this question ; if further research shows that the views of to-day are untenable, 
I shall be ready to receive that fresh light. 
When the development of the skull has been worked out in Family after Family 
in the Orders that compose the whole Class, then will be the time for a general 
