Monthly Microscopicall 
Journal, Feb. 1, 1869. J 
A New Infusorium. 
117 
VII. — On a New Infusorium. By J. G. Tatem. 
Feom a receptacle for the discarded contents of collecting-bottles, 
■which has been long exposed to the open air — a mixture therefore 
of rain-water and pond- water, from many localities, and now parti- 
cularly offensive from decaying animal and vegetable matter — I 
have recently obtained an animalcule which has hitherto, I believe, 
escaped observation. 
It occurs as both a free swimming and invaginated ciliated 
Infusorium. (See Plate lY.) 
In the free swimming condition it is oblong, transparent, faintly 
plicate transversely, ciliated all over, the cilia fine, not arranged in 
longitudinal rows, longest at the terminal anal outlet, which is 
situate not quite in the axial line, but slightly lateral to it, and 
rather prominent. The oral aperture is seen in this stage as a 
raised margin or lip, edged with long cilia. The food-vesicles are 
numerous, crowded, and of a bright claret colour. 
In the invaginated form, while at rest, it maintains precisely 
the same general outline and appearance. The investing sheath is 
firm, resisting, and perfectly hyaline, vase-shaped, with a somewhat 
patulous mouth, narrowing into a neck behind, then swelling into 
an ample, slightly corrugated body (the sides of which are, how- 
ever, straighter in some examples than in others), with a truncated 
base, to which the contained animal is wholly unattached. Kising 
in its sheath when feeding, and elongating into a short neck as it 
presses forward, the mouth opens just below that of the sheath, as 
a circular orifice with a thickened margin, surrounded by a simple 
wreath of cilia, which creates an extended vortex around it. A 
short infundibulum conveys the food particles into the vesicle, 
which originates at its extremity, and in which the usual active 
rotary circulation is observed. It is noticeable that in this nascent 
food- vesicle colour is but faintly indicated. May not therefore the 
bright claret hue of the others be attributable to the chemical 
action of the assimilative process? It is certainly voracious, — 
vibriones, monadina, and minute particles of decaying vegetable 
matter are greedily absorbed. 
Impatient of restraint, within a few minutes after being placed 
in the cage, in most instances it makes a hasty exit from its sheath, 
squeezing itself through the neck with difficulty, and leaving behind 
a considerable amount of foecal matter, of the same bright colour as 
the food-vesicles, which in the cases of the larger masses is extruded 
through a positive rupture of the integument. It then swims off 
with the motion and general character of a Stentor, for a small 
species of which a careless observer might readily mistake it. 
VOL. I. K 
