president’s ADDRESS — SECTION D. 
101 ' 
o£ the wood. This I attribute to the action probably of some 
mycetozoon. In other cases the wood is simply mouldy, like old 
cheese, while in others it supports in its interstices a perfect garden 
of most exquisite fungi. These fungi doubtless afford a supply of 
food to many small animals. 
The cryptozoic fauna has been recruited not only from many 
distinct classes of the animal kingdom, but from several distinct 
faunistic groups, and it appears to me that it may thus be divided into 
four sections, distinguished by their mode of origin : — 
(a.) Representatives of typically terrestrial groups of animals 
tvhich are dominant at the present day. — These may be found in all 
stages of development. This section is much the strongest, both in 
numbers and variety. It includes, for example, many insects, especially 
ants, beetles, and cockroaches ; many spiders, many centipedes and 
millipedes, and many slugs and snails. Of course all these, in common 
with other terrestrial animals, have doubtless been derived iu the 
first instance from aquatic ancestors ; but they have become so 
modified in structure in accordance with their change of habitat and so 
dominant on the land, as to entitle them to be considered as typically 
terrestrial. 
(/>.) Surviviny members of extremely ancient y roups which are now 
almost extinct . -In this section we may perhaps include the scorpions, 
which arc of extreme antiquity, dating back to the Silurian epoch, 
and which can hardly bo considered as a dominant group at the 
present da}’. In addition to these I know of only one genus which 
belongs here, and that of course is the remarkable Reripatvs , which 
has attracted so much attention during the last few years, and which 
is perhaps the most interesting member of the cryptozoic fauna. These 
primitive types appear to have successfully evaded the struggle for 
existence by taking refuge iu obscure retreats. 
(c.) Immature forms of terrestrial animals which are not cryptozoic 
in the adult condition. — This section includes the larva? of various 
insects of which the adults live in the open. 
(d.') Isolated representatives of typically aquatic groups of animals 
which have as yet become but little modified in accordance with their 
new mode of life. — This division is both large and of exceptional 
interest, for we find in it many animals which are, so to speak, in a 
transitional condition between aquatic and terrestrial, and we may 
perhaps gain much information from them as to the manner in wdiich 
this great transition from an aquatic to a terrestrial mode of life has 
been effected. Every naturalist knows how many small animals 
swarm beneath half-dry stones on the sea shore. Such species appear 
to me to be taking the first step towards a terrestrial life. Gradually 
they will make their way inland, still keeping beneath logs and stones 
for the sake of moisture and coolness, until finally they accustom 
themselves to a thoroughly terrestrial existence. 
In this section of the cryptozoic fauna we must place the shrimp- 
like Amphipoda and Isopoda , which certainly look strangely out of place 
on land, together with the remarkable Land Planarians, so abundant 
and varied in Australasia, and the still more remarkable Land 
Nemertines. 
