CHAIN OF CYCLOSALPA AFFINIS 433 
be fully known without having been fully studied. This concep- 
tion of nature and the knowledge of nature is always and every- 
where the begetter of dogmatic assertion on the part of leaders, 
of subserviency to authority on the part of followers, and of idol- 
atry to certain facts and neglect of others by everybody. This 
is not the place to go into the logic, or rather, the epistemology, 
of biology. The case under treatment does, however, justify us in 
a few observations and reflections on procedure in research. 
Why is it that the biological sciences are designated as obser- 
vational and descriptive, to distinguish them from the physical 
sciences which are called quantitative and exact? Surely no 
present-day student of nature would contend that living objects 
are qualitative alone and so must be dealt with in terms of quality, 
while non-living objects are quantitative and are to be dealt 
with in terms of quantity! There is surely no structural part or 
activity of any organism that does not exist in some quantity 
or other, and hence is not susceptible of being measured in some 
way. Contrarywise, there is surely no inorganic body or sub- 
stance that has not qualities of some sort by which it is described 
and defined. Yet why is it that in spite of the brave effort made 
by a few distinguished men of science during the last half century 
to introduce conceptions of quantity and the methods of mathe- 
matics into biology, these efforts have met with only limited 
success at best, and are ignored in practice and frowned upon in 
theory by many of the foremost bilogists? Only a few months 
ago a distinguished investigator declared in the presence of the 
senior author of this paper that the quantitative method in biol- 
ogy is dead, and this student suiting practice to theory, though 
working in fields where quantitative conceptions and exact de- 
terminations are particularly important, rarely attempts to meas- 
ure in any rigorous way the biological phenomena with which 
he deals. Attention cannot be called too strongly to the extent 
to which much of what is esteemed the very highest type of recent 
biological work has laid stress on accurate quantitative determi- 
nation of certain environmental factors of organisms, but has 
ignored almost wholly quantitative determinations of the vital 
phenomena themselves. There can be no question about the 
