162 MR. F. CHAPMAN ON FORAMINIFERA 
reached at Fuafatu Islet *. These dredgings were sent over in 
6 oz. capsuled bottles and numbered consecutively 1 to 18. 
The starting point for the dredgings, Fongafale, presents an 
unbroken rim; but on the contrary Fuafatu, on the opposite side 
of the Atoll, is situated on the part of the rim which is broken 
up by channels. These diverse features afford most interesting 
comparisons of the foraminiferal faunas at the two localities; for 
at the former place the Foraminifera have lived under more or 
less tranquil conditions; whereas those of the latter locality 
were subjected to the action of the currents and surf, and 
consequently had an abundant food-supply, and this could not 
tail to make a decided difference in the assemblage found 
there. 
Although the lagoon of Funafuti is open to the sea by many 
broad channels, chiefly on the 8.E. and N.W., the area itself is so 
large, about 9 miles along the line of the soundings, that we 
might well expect to find a facies in the middle of the lagoon 
differing from that near the rim of the Atoll. 
The results obtained not only bear out this expectation, but 
they offer many new points with regard to the habits and pre- 
ference of conditions exhibited by such lowly forms as the 
Rhizopoda, far exceeding anything we had anticipated. 
The present collection is a remarkable object-lesson on the 
importance of environment in producing variations ; and provided 
these conditions remain fixed for lengthened periods, the varieties 
may converge to definite centres of form, and come to be regarded 
as species. The simplicity of the Rhizopod-structure and the 
almost infinite adaptability of these animals to their environ- 
ment enable us to point to innumerable connecting-links or 
intermediate forms, the despair of the systematist, which afford 
the biologist material for some important deductions and a general 
comparative study. 
The present work has been chiefly carried out in the Geological 
Laboratory of the Royal College of Science; and I am indebted 
to Prof. Judd, C.B., F.R.S., for the facilities he has there given 
me. 
* See Map of Funafuti Atoll, p. 167. 
