TRANSACTIONS OF SECTION D. 525 
in different geological epochs, so that all rabbit-like members of the family did 
not form one well-circumscribed group as opposed to the hare-like ones, but, on 
the contrary, they represented a number of independent side branches emerging 
on different levels from a central stem, that itself leads from primitive hares 
like the Sumatran short-eared hare called Nesolagus netscheri, to the highest 
developed species, as Lepus europeus. Thus the hispid hare of Bengal, living 
on the southern slopes of the Himalayas, known as Caprolagus hispidus, accord- 
ing to my views, is to be considered as a rabbit-like offspring of primitive short- 
eared hares still represented by Nesolagus. 
Another group of mammals about which I may presume to pronounce personal 
judgment are the Monotremes. Ornithorhynchus and Echidna are both highly 
specialised forms, whose more generalised ancestors have all disappeared from 
the globe, and their similarities in many points are the consequence of con- 
vergence instead of homology. So it is by general consent with the loss of their 
teeth, but, according to my view, the same is the case with the retrogression of 
their internal nares and the corresponding elongation of their bony mouth-roof. 
Ornithorhynchus acquired these features on account of its amphibian habits, as 
was the case with the crocodiles or the Cetacea. Echidna, on the contrary, 
developed them under the influence of its ant-diet, as did the South American 
ant-eaters and the aardvark of the Cape. Yet the arrangement of the bones 
in these osseous roofs of the mouth-cavity shows a similarity of primitive 
character, which, without doubt, depends on common ancestry, and therefore 
may be used in phylogenetic speculations. The same is true of many other 
features; for instance, the annular tympanic bone, the large malleus, the unper- 
forated stapes, the possession of marsupial bones, the number, position, and 
anatomical structure of the milk glands, and so on. In my opinion, the pheno- 
mena of convergence, even in nearly related organisms, will never prove to be 
a serious obstacle to the disentangling of phylogeny. 
(iv) Convergence and Allied Phenomena in the Mammalia. 
By W. K. Greaory, Ph.D. 
In his monograph on the Shoulder-girdle of the Vertebrata the late W. K. 
Parker spoke scornfully of the study of Adaptation. A teleological explana- 
tion, he said, is an impertinence in a morphological work; and again: ‘Tele- 
ology is a pretty golden ball that diverts the racer from his course.’ But at 
present it is coming to be realised that studies on Adaptation (of which Con- 
vergence is a special case) must be thoroughly synthetised with morphology, 
general phyletic relations, and taxonomy. 
The frequency of homoplastic resemblances and the discovery that certain 
systematic groups are unnatural should lead to no pessimistic views regarding 
classification and phylogeny in general, but rather to encouragement. For, at 
least in every case which I have thoroughly studied, Convergence never leads 
to a complete agreement in underlying ordinal or subordinal characters between 
convergent forms of widely different ancestry. By close study of the skeleton 
and soft parts the many little things that reveal the true phylogenetic positions 
of the convergent forms become apparent. 
Specimens of the skulls of the Marsupial Wolf Thylacinus and of the ordinary 
wolf were exhibited, and it was argued that, notwithstanding the marked 
“ cenotelic’ resemblances, the ‘ palwotelic’ differences showed conclusively that 
one was a Marsupial, the other a Placental. Similarly the ‘cznotelic ’ charac- 
ters of Notoryctes give it a marked general resemblance to Chrysochloris, but 
the palzotelic characters of the two forms show that one is a specialised Poly- 
protodont Marsupial, the other a specialised Zalambdodont Insectivore. 
The totality of the czenotelic or recent adaptive characters of an animal 
may be called its habitus; the totality of its paleotelic characters may be 
referred to as its heritage. The habitus tends to conceal remote phylogenetic 
relationships, the heritage to reveal them. Thus, the diverse habitus of 
Thylacinus, Notoryctes, and Phaseolomys concealed their remarkably uniform 
underlying heritage. é 
In many cases of Convergence there is a likeness of material or a general 
homology to begin with, as in the evolution of the Carnassial teeth in the 
