250 
probable that the white corpuscles, either in the capillaries 
or lymphatic glands, collect during their amcebaform move- 
ments, those germs of bacteria, which my own experiments 
(‘American Journal of the Medical Sciences,’ July, 1868) in- 
dicate always exist in the blood to a greater or less amount. 
And further, it appears not impossible that, when thus loaded, 
their elimination through the saliva, under the mercurial in- 
fluence, and their evacuation by a discharge of pus from a 
seton or a tartar-emetic ulcer, really constitute that thera- 
peutic value of these remedial measures in certain cases which 
has so long rested unexplained. 
On Some Freshwater Rhizopoda, New or Liitle-known. 
By William Archer. 
With Plates 1 XVI and XVII. 
The microscopist, in the course of his examination of his 
gatherings made from pools and ditches, be the objects of his 
research what they may, cannot fail to encounter certain 
ordinary representatives of the group, to some new or little- 
known forms of which, I am, in the following communication, 
very cursorily about to draw attention ; and this, indeed, 
rather by hardly more than simply pointing to the figures, 
than by assuming to throw upon them an additional light 
by any special observations. 
Although the Rhizopoda are a group of which the sea 
harbours the greatest variety, as well as the most beautiful 
forms, yet are those which find a habitation in the fresh 
waters far from being without their interest — nay, few other 
animal groups have of late awakened more lively attention. 
Therefore such a communication as the present — even though 
it but humbly essays to bring to notice some types which 
seem rarely or not before to have met observation in the fresh 
water, without being able to add to our knowledge in a 
physiological point of view as regards these lowly beings — 
may not, perhaps, be wholly destitute of value or interest. 
Such, indeed, is the frequency with which certain fresh- 
water forms are met with, that no observer with the micro- 
scope can fail to be more or less familiar with the commoner 
species ; again and again they present themslves, and, to my 
eyes at least, they seem again and again ever recognisable ; 
1 The two folding coloured plates (XVI, XVII) illustrating this paper, 
will appear in October with the rest of the paper and drawings. 
