VAMPYRELLA LATEE1TIA. 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 Moiigeotia-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 Vampyrella 

 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 Spirocjyra" 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 Vampyrella 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 

 place. 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 Vampyrella 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 Naturellos/ tome xxii, p. 523. 



