VAMPYRELLA LATERITIA. 99 
itself to the cell very soon had perforated it, a portion 
of the animal protoplasm passing into the cell and 
causing a violent dancing movement of the granules of 
the vegetable protoplasm. Whilst this was happening 
the chromatophore of the Mougeotia-cell was observed 
to be disintegrating- at a point immediately opposite 
the place of attachment of the animal. I watched this 
destruction go on for about two hours; it was accom- 
panied by much violent movement on the part of the 
small granules of the protoplasm, but during that time 
only a portion of the chromatophore and surrounding 
protoplasm of the vegetable cell had been absorbed by 
the Vampyrella.” 
The exertion of force by an individual Vainpyrella 
explains its action, in this case as in the other. This 
was pointed out by Penard so long ago as 1889, in a 
paper communicated to the Physical and Natural His- 
tory Society of Geneva.* “The Vampyrella is said 
to pierce a hole in the cell of Spirogyra,” the author 
remarks, “and to introduce into it a pseudopodium, the 
business of which is to search the contents of the cell. 
The phenomenon, which I have observed repeatedly, 
may be described thus: The lwmpyrella attaches itself 
to a cell of Spirogyra, retracts its pseudopodia, except 
a few by which it adheres to the alga, and then moulds 
itself to the cell upon a portion of its surface, and 
becomes motionless. For a moment nothing takes 
lace. Then we see the attached zone rise up into 
an arch in the interior, the margins remaining firmly 
attached and formed into a ring; the arch gradually 
rises, and suddenly the wall of the alga bursts, the 
cell-juice of the Spirogyra passes in a violent stream 
into the Vampyrella; the greyish plasma of the cell 
passes, in its turn, more slowly, with the green chro- 
matophore, which is seen to glide in a mass; the cell 
is completely emptied ; the Vaipyrella emits pseudo- 
podia, becomes detached, and moves away, leaving a 
very visible rupture in the empty cell. It then goes 
* «Archives des Sciences Physiques et Naturelles,’ tome xxii, p. 523. 
