FOURTH JOURNEY TO THE SOUTH SEAS 151 
restricted to particular islands. ‘The climatic and other conditions were 
so adyerse that a complete exploration was impossible in Samoa at this 
time of the year. In Tutuila, however, which is the largest island of 
American Samoa, a practically complete survey was made, and much 
interesting material was secured. The high mountain slopes covered 
with dense vegetation are pictured on page 129. They are like those of 
the Society Islands, but the intervening valleys are not as rigidly isolated 
as in the latter region, so that the species of different parts of the islands 
resemble one another quite closely. Our interest here centers in the 
comparison of Samoan species with those of other groups. 
The Fiji Islands, next in order, belong ethnologically and geologically 
to Melanesia, a quite distinct region of the South Pacific. Ovalau and 
Viti-Levu were visited, but no species of Partula were found in them; 
the single form from this group that is known to science occurs in more 
remote islands. It seems strange to one familiar with southeastern 
Polynesia that the Partulas should be lacking, for the thick, moist jungle 
(page 130) and the topography seem to be in every way the same as in 
the eastern islands. Going next to the Hawaiian Islands, I spent consid- 
erable time in studying the famous collections in the Bishop Museum 
which were made by Andrew Garrett during decades of research in the 
islands of the Pacific. Most of the original forms had been discovered 
during Garrett’s explorations, and so his collections with his own identi- 
fications must always have great value for the student of the present day. 
Through the kindness and courtesy of Dr. C. M. Cooke of the Bishop 
Museum, excursions were made into the field in the island of Oahu, in 
order to observe personally how the Achatinellid land-snails resemble 
and differ from the Partulas in biological relations. ‘The remarkable 
fact resulting from this comparison is that the former snails are re- 
stricted to isolated trees or clumps of trees on the sides of the valleys, 
while the drier and more open valley-bottom forms the barriers, instead 
of the ridges as in the case of the Partulas. The essential principles of 
distribution, however, are the same. 
The zoélogist who travels more or less extensively in the South Seas 
soon becomes an ardent student of the native inhabitants. His interests 
would be aroused by the primitive daily occupations and culture of the 
people who, nevertheless, have developed remarkable inte!lectual powers; 
but the feature of greater significance to the investigator of the principles 
of geographical distribution is the fact that precisely similar phenomena 
