XI. 
NOTES ON THE PROTOZOA OF HERTFORDSHIRE: SECTION 
DISCOSTOMATA. 
By F. W. Phillips, F.L.S. 
Head at Hertford , 28 th February, 1884. 
PLATE VI. 
Duping the last session I had the honour of reading before this 
Society the first of a series of papers having for their aim the 
record of those species of the Protozoa which have been found in 
the county. In that paper I gave an account of the lowest and 
simplest forms of life known to science—mere specks of animated 
jelly—having neither mouth nor any other organ whereby food 
can be taken into the body, and subsisting by the mere absorption of 
small or invisible particles contained in the liquid medium through 
which they move; the majority of these creatures often being of 
so small a size as to defy the highest powers of the microscope. 
Upon this first section has been bestowed the name Pantostomata, 
a word meaning “ all mouth.” 
I now purpose giving an account of the second section, 
called, in reference to the circumscribed area in which food can be 
incepted, Discostomata. This section, as I shall presently show, 
is closely allied to the previous one ; the line of division which has 
been drawn is simply one of convenience, having no real existence ; 
indeed, this is the case with all other such lines of demarcation. 
One cannot go very far into the study of plant- or animal-life 
without finding that there is no such thing as a hard and sharp line 
or division in the whole realm of Nature, but one gradually 
ascending scale, from the lowest forms, up to man himself. The 
present section, which I am about to describe, is one of those which 
have a peculiar fascination for the biologist, because, although the 
members thereof are of so lowly and humble a nature, yet they are 
rich in those foreshadowings, as it were, of organs which belong to 
more highly-organised creatures. 
A further interest centres in this section, because a knowledge of 
it is the harvest of the most recent microscopical research; the long 
immunity from investigation which this group has enjoyed being 
doubtless due to their excessive minuteness. Compared with them, 
the larger number of the ciliate infusoria with which we have 
been so long familiar are very giants. The “tiny vorticella” is 
often spoken of as an emblem of minuteness, and yet its spirally-un¬ 
folding stem is the world upon which many of these creatures live. I 
will not inflict upon you a number of figures, but content myself with 
the statement that the largest individual does not exceed the one- 
thousandth part of an inch in length, while the average dimension 
may be computed at the inconceivable size of the three-thousandth 
part of an inch. 
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