TRANSACTIONS OF THE LINNEAN SOCIETY. 
THE PERCY SLADEN TRUST - EXPEDITION 
TO 
THE INDIAN. OCEAN IN 1905, 
UNDER THE LEADERSHIP OF — 
Mie. otANLEY GARDINER. 
No. I—DESCRIPTION OF THE EXPEDITION. 
By J. SvantEy Garpiner, A., F.L.S., Fellow of Gonville and Caius College 
and Demonstrator of Animal Morphology in the University of Cambridge, 
and C. Forster Cooper, I.A., Trinity College, Cambridge. 
(Plates 1-10 and 23 Text-figures.) 
Read 21st February, 1907. 
CoNnTENTS. 
Page 
PALM RO MICE ONS A SPRAY Saves clo cloves sis eld cum oh. achalacstsbalehnuscelevsls + ole ohorehels 1 
IJ. History and Equipment of the Expedition ....................00sce0n 8 
III. Summary of the Voyage and Work.—Part I. Ceylon to Mauritius ........ 21 
I. INTRODUCTION. 
MEN of science have always been attracted by the study of the former distribution 
of land and water upon our globe. We see continual modifications caused by the 
action of large volumes of water upon its shores, also by rain and wind, by heat 
and frost, by subterranean explosions, and so forth. We are led, in the hope of 
prophesying the future, to enquire to what extent these agencies are at work in 
altering the face of the habitable world at the present time. 
A glance around reveals to us a numerically large series of organisms, endowed with 
life and with powers of growth and reproduction. We require to know those changes 
in our world through which their ancestors have lived—changes which without doubt 
have largely moulded their present morphological forms. Cases are known of similar 
organisms occurring in strictly localised situations, often widely separated, even to 
the extent of having half the globe between them. Such a phenomenon at once arrests 
our attention, and we search for reasons for so extraordinary a distribution. Were only 
a few such cases to occur, we might be tempted to pass them by as a matter of chance 
SECOND SERIES.—ZOOLOGY, VOL. XII. 1 
