90 
OCEANIC ISLANDS. 
Apk., 1890 . 
miles wide—has its history first as a Dutch naval station, 
then as a depot for privateers, and lastly and to this day as a 
convict station for Brazil. It has, therefore, been somewhat 
difficult of access, both Mr. Darwin and the “Challenger” 
having been refused permission to collect specimens there. 
It was, however, visited in 1887 by Mr. H. N. Ridley, M.A., 
F.L.S., then of the British Museum, and now of the 
Botanical Gardens, Singapore, with whom were Mr. G. A. 
Ramage, of Edinburgh University, and myself. We stayed 
there six weeks, and the results of our work will shortlv be 
published by the Linnean Society, the specimens being lodged 
in the British Museum. It is thus that most of my observa¬ 
tions on this subject were made at Fernando de Noronha, 
though the problem is the same in the Hawaiian Islands as 
there. Like the Hawaiian Islands, Fernando is volcanic, but 
its age is very great, and there are no traces of any recent 
activity. And thus while I chose the former as an example 
of the construction of an oceanic island, I shall take the 
latter as an illustration of the present condition, and as also 
indicating the future of such places; though what I shall say 
of it is true also, within certain limits, of Hawaii, and even of 
New Zealand and Australia. Taking the flora and fauna of 
Fernando de Noronha as they stand at present, the species 
may be divided into two classes, the adventitious and the 
indigenous. The adventitious species may be again sub¬ 
divided into those which have been intentionally and those 
which have been accidentally introduced by man from else¬ 
where. Intentional introductions, such as fruits, vegetables, 
etc., may be dismissed, but the accidental are more important. 
Nobody purposely introduces rats and weeds to any new place, 
but the rats and weeds find their way of themselves, and have 
a great habit of making themselves at home. In so doing 
they bring about very considerable changes, as I shall indicate. 
The other species which I classed as the indigenous ones may 
be grouped under three heads. First, the creatures of the 
shallow water near the shore. These are as much confined 
by deep water to their particular location as the land species; 
or, to explain by an instance, a worm which inhabits rocks is 
not adapted for an ocean voyage. Thus though there was 
little absolutely peculiar to the Fernando coast it was noticed 
that the general aspect was much more that of West Indian 
waters than that of the much nearer Brazilian coast. 
Secondly, just out of reach of the waves grew many land 
plants, of which Ipomoea Pes-capne, a splendid crimson con¬ 
volvulus, may serve as a type* These are plants whose seeds 
being numerous and not liable to damage by sea water may be 
