DS. REPORT—1862. 
hypothesis of the cause of these homologies, with their structural gradations and 
differences, would abrogate the necessity of the zoological disposition of the differ- 
ent members of the animal kingdom in groups of different degrees of value. The 
modification of the human foot having been, in the author’s opinion, rightly esti- 
mated by Cuvier as of ordinal value, he contended that the equal or correlative 
degree of difference shown in the development of the human brain, regard being 
had to the higher importance of that organ in the animal frame, necessitated its 
higher appreciation as a zoological character, and that the now known characters 
of the Gorilla’s brain confirmed the reference of the Bimanous order to the subclass 
Archencephala. 
On the Homologies of the Bones of the Head of the Polypterus niloticus. 
By Professor R. Owen, M_D., F.RS., F.GS. 
Preparations and sections of the skull of the Polypterus were exhibited, showing 
the way and proportions in which the bones of the exo- and endo-skeleton were 
blended together, more especially the extension of the epencephalic segment 
backward freely beneath the overarching roof of dermal bones, roi which the 
super-, ex-, and par-occipitals were distinct. Professor Owen referred to a para- 
graph in his ‘ Lectures on Comparative Anatomy’ (vol. ii. p. 136), in reference to the 
inconstancy of the dermo-cranial bones of the Sturgeon, and the confusion caused by 
applying to them the names ‘super-oecipital,” “par-occipital,” or other synonyms 
of the vertebral elements of the skull. The same remark applies to Polypterus, 
Lepidosteus, and many extinct Ganoidet. 
On Zoological Provinces. By Six J. Ricwarnvson, F.R.S. 
This paper consisted mainly of a single question, “ What is a zoological pro- 
vince?” A right and full answer would, in the author’s opinion, open one avenue 
to the solution of the origin of species which has occupied the naturalists of this 
country for several years. 
He referred to the Palmipede group of birds, The highest latitudes of the Arctic 
regions to which man has penetrated are the native places of the Snow Goose, and 
of various other members of the family, who, having reared their young in two brief 
months, speed to the southward and winter on the verge of the tropics. Is this 
whole space, little less in extent than a hemisphere, to be accounted a zoological 
district ? 
The range of the Whale is not far short; but land-animals have a much less 
wide distribution. Has every class of the Vertebrata a different zoological pro- 
vince? and how far are any of them conterminous with the provinces marked out 
by botanists ? 
On certain Modifications in the Structures of Diving Animals, 
By Prof. Rorrustoy, M.D., F.R.S. 
In the class Mammalia, the Cetacea were contrasted with the Phocide, and in 
the class Aves, the Colymbidz were contrasted with the Cinclide, as to the 
degree of modification which their tegumentary, circulatory, and osseous systems 
had undergone in adaptation to their aquatic habits. 
The skin of the Seal was less specially modified than that of the Whale, and 
the aberrations from the ordinary Mammalian character which its bones and teeth 
presented were in like manner less marked than those of the animals with which 
it was compared. The teeth in the order Seals were often irregular as regarded 
their number, their implantation, and their permanence in the jaw; and the 
epiphyses of the vertebrae were often slow to unite with the bodies. All these 
particularities were instances of correlation of growth existing between the skin and 
medullares proficiscuntur, inque fundo cornu posterioris plicas graciles et retroflexas for- 
mant, in cerebro Simiarum desunt; nec in cerebro aliorum a me examinatorum mamma- 
lium occurrunt ; Homini ergo proprii sunt.” (Ib. p. 51.) Both the above propositions 
are susceptible of flat contradiction on homological grounds, and are, nevertheless, true as 
zoological characters. 
