president’s ADDRESS — SECTION D. 
107 
envelopes may also be indicative of an affinity with insects rather than 
with worms. Oil the other hand, Peripatus has certain structural 
features peculiar to itself, such as the slime glands and oral papillae. 
For these reasons it has been proposed by Haeckel to place 
P crip at us in a group by itself, and to this group he has given the 
name Protracheata . AVe may suppose the Protracheata to be 
descended, without very much modification, from the common ancestor 
of worms and insects, although probably, as Captain Hutton observes, 
they cannot be considered as a direct link between these two groups. 
Even apart from its anatomical peculiarities, the geographical 
distribution of Peripatus seems to indicate that it is an extremely 
ancient type. Like other forms which we have reason to believe are 
of great antiquity, it is now found at the southern extremities of the 
great land masses : at the Cape of Good Hope, in South America, and 
in Australia, as well as in various islands, as New Zealand and the 
West Indies. This peculiar distribution is accounted for on the 
supposition that Peripatus , like other forms of life, had its origin 
somewhere in the great land mass of the northern hemisphere, and 
that, owing to competition with improved and more perfectly adapted 
forms in the north, it was gradually driven to the southern extremities 
of the great continents, where the few surviving species now find a 
refuge in cryptozoic haunts. 
That the differentiation of the species in these widely-separated 
localities has not gone sufficiently far to have become of generic 
importance in the eyes of the great majority of naturalists is a very 
noteworthy fact, probably indicating that Peripatus is a very per- 
sistent type, subject only to very slow modification. This persistence 
of structure is, perhaps, to he attributed to the similarity of the 
conditions under which Peripatus always lives, and to the more or less 
successful escape from the general struggle for existence in its hidden 
retreats. 
It must be pointed out, however, in this connection, that Mr. 
Pocock has quite recently proposed* * * § to subdivide the genus into three, 
using the name Peripatus for the Neotropical species, Peripatoides for 
the Australasian species, and Peripatopsis for the South African 
species. The anatomical differences upon which this classification is 
based are, however, very slight, concerning only the number of spinous 
pads on the legs and the distance of the generative aperture from the 
hinder extremity. 
The history of our knowledge of the Australian species of 
Peripatus up to duly, 1889, is given at some length in my observations 
on the subject, published by the Eoyal Society of Victoria, t wherein 
references will be found to the earlier writings of Saenger, Tryon, 
Fletcher, and Sedgwick. As we are at present dealing with New 
Zealand as well as Australian species, we must add to this list the 
important memoir by Captain Hutton on Peripatus novce-sealandicBy 
published nearly twenty years ago,J and the recent observations by 
Miss Sheldon § on the development and anatomy of the same species. 
* Journal of the Linnean Society of London, vol. xxiv., p. 518 (1894). 
tProc. Royal Soc. Victoria for 1889, p. 50. 
X Annals and Magazine of Natural History, November, 1876. 
§ Quarterly Journal of Microscopical Science. 
