THE COLLECTIONS FROM TAHITI AND THEIR INVESTIGATION. 35 
THE COLLECTION, TREATMENT, AND ANALYSIS OF THE MATERIAL. 
Field-work in such a region as Polynesia presents difficulties that are common to 
most tropical areas in the way of access, climate, and travel about the islands. As 
a rule, steamship lines ply between only the principal ports, from which excursions 
to neighboring islands must be made by cutter, whaleboat, or canoe. The same 
means must also be employed in journeying about the periphery of a single island, 
although at times it is possible to procure horses, as in most of the work in Tahiti. 
Almost without exception, however, the exploration of a valley can be accomplished 
only on foot, owing to the steep declivities to be traversed, the deep streams to be 
forded, and the absence of any trails whatsoever in the thick forest and undergrowth 
of the areas inhabited by Partule. 
It was my custom to start in the early morning with two or three native assist- 
ants, more rarely alone, and to spend the greater part of the day in the interior. 
Full notes were made as to the character of the vegetation, the favored nurse-plants, 
the topographical features, the inland distances and barometric levels of the points 
where snails were first met and of their headquarters in a given valley, as well as 
other pertinent facts. The experiences incidental to the active life necessitated by 
such work were many, varied, and interesting; but the present monograph is not 
the place for a description of the beautiful islands or of their delightful inhabitants. 
Suffice it to say that the days and nights of arduous and sometimes dangerous effort 
included hours of keen enjoyment, for the island of Tahiti, especially, is of matchless 
beauty, while the chiefs and their families offered abundant hospitalities which it was 
a privilege to enjoy at the time as it is now a pleasure to acknowledge them. 
Having secured the snails, the return to the coast was made, and the animals were 
put in glass jars filled with fresh water so as to exclude the air. After a few hours, 
the animals were expanded in an asphyxiated condition, whereupon formalin in 
due quantity was poured in as a preservative. Alcohol alters the color to some 
extent, while formalin does not. Care must be taken to free the material from 
foreign bodies, such as bits of leaves or sticks, and to keep the preservative from 
contact with metal, else the colors of the shells will be altered by the decomposed 
or otherwise changed fluid. 
The exigencies of field-work do not permit more than a cursory study of the 
material before it is brought back to the laboratory where analytical work begins. 
Carefully segregated, valley by valley, the snails are then classified according to 
species, variety, and class or subordinate variety. Often the assortment into con- 
stituent groups must be repeated on the basis of what may be discovered in the study 
of a neighboring colony. Then follows the time-consuming labor of measuring the 
shells, arranged serially in divisions according to their qualitative characters; the 
dimensions were measured to tenths of a millimeter. At the same time that such 
quantitative data are obtained, the more or less extended body of the animal is 
extracted, and if the individual is gravid, the number of eggs and young snails is 
noted, as well as the data relating to the color and coil of embryonic shells. The 
adults are then marked with their serial number, so that later reference may be 
made to any individual shell should occasion arise. The author is personally 
