TRANSACTIONS OF SECTION D. 553 
actually obtained ; or, to put it another way, had two expeditions taken samples 
that evening at what might well be considered as the same station, but a few 
hundred yards apart, they might have arrived at very different conclusions as te 
the constitution of the plankton in that part of the ocean. 
It is interesting to note that enormous numbers of Ozkopleura ‘ houses’ covered 
with diatoms were present in some of the gatherings during April, and that the 
abundance of the diatom 7halassiosira Nordenskioldii was phenomenal. We have 
some reason to think that there has been an exceptional flow of cold water from 
the north into the Irish Sea this spring, and that may account for the presence of 
this northern diatom which has not been found in our region before. 
As an example of two surface-nets hauled together, which gave much the same 
quantity of plankton, but where the gatherings differed widely in their nature, 
I may give the details of April 13, when net A had 16 c.c, and net B 155 c.c., 
while the prevalent organisms were present in very different proportions in the two 
cases. [Table shown and details explained. | 
The bearing of such observations as these upon some recent speculations as to 
the fish population of the sea, and even as to the amounts of food matters present 
in the waters of large areas, isobvious. Nothing in the economics of the sea could 
be more important than such speculations in regard to what I have proposed 
should be called the ‘hylokinesis’ of the ocean, if we could be certain that our 
conclusions are correct, or even that they are reasonably close approximations. 
It is possible to obtain a great deal of interesting information in regard to the 
hylokinesis of the sea without attempting a numerical accuracy which is not yet 
attainable, The details of measurement of catches and of computation of organ- 
isms become useless, and the exact figures are non-significant if the hauls from 
which they are derived are not really comparable with one another, and the 
samples obtained are not adequately representative of Nature. If the stations are 
so far apart, and the dates are so distant, that the samples represent little more 
than themselves; if the observations are liable to be affected by any accidental 
factor which does not apply to the entire area, then the results may be so erroneous 
as to be useless—or worse than useless, since they may lead to deceptive con- 
clusions. 
My view in brief is (1) that we must investigate our methods before we 
attempt_to investigate Nature on a large scale; (2) that we must find out much 
about our gatherings of organisms before we can consider them as adequate 
samples; and (3) that we must make an intensive study of small areas before we 
draw conclusions in regard to relatively large regions such as the North Sea or the 
Atlantic Ocean. 
4, Demonstration : Models of Protozoa. By F. R. Row ey. 
5. Experiments on the Development of the Frog. 
By Dr. J. W. Jenxinson.—See Reports, p. 347. 
6. The Classification of the Haplosporidia. 
By H. B. Fantuam, B.Sc., A.K.C.S. 
The Haplosporidia are parasitic Protozoa belonging to the class Sporozoa, and 
are a simple and probably primitive group near the base of the Neosporidia, for 
their reproduction takes place during the trophic phase. 
The group Haplosporidia was founded by Caullery and Mesnil in 1899. As 
the name implies, the spores are simple—without polar capsules—and are uni- 
nucleate. The parasites occur in Rotifers, Annelids, Crustacea, and Chordates. 
The order, as originally defined by Caullery and Mesnil, has been extended recently 
to include a parasite, Rhinosporidium kinealyi, from the septum nasi of man, 
