44
IX. Infusoria : What are they? Their Collection and
Investigation.
By W. Saville Kent, F.L.S., F.Z.S., F.R.M.S.
[An Address delivered at the Field Meeting held at Chigwell, June 25th,
1881.]
It has been my privilege to accompany you this afternoon
in your pleasant Field Meeting in the search for microscopic
spoils, and more particularly to assist you, so far as circum-
stances would permit, in the collection of the special objects
of my investigation, namely, Infusoria.
Although Jupiter Pluvius has unfortunately been so unpro-
propitious as to seriously interfere with our good intentions,
I yet purpose now to address you briefly upon the more
important features of this highly interesting organic group,
trusting that the remarks I make may induce some, or,
I would even hope, many, members of the Essex Field Club
to embark also upon its systematic study.
It is in the first place desirable that I should place before
you a concise definition of the series of organisms that, in
accordance with our present knowledge, have to be included
within the Infusorial world, such definition being requisite to
enable the student to know what to accept and what to reject
from among the multifarious forms that will present them-
selves to his notice at the very outset of his investigations,
and which were actually comprised in the group by the
earlier authorities. Even the latest complete treatise in the
English language, Pritchard's 'History of the Infusoria,'
that relates to this organic group, is based upon the lines
laid down half a century ago by C. E. Ehrenberg, and
includes, in a similar manner, a heterogeneous assemblage of
animal and vegetal organisms belonging to half a dozen or
more distinct classes (Diatoms, Desmids, Rotifers, Rhizopods,