AMONG SIMPLE SAKCODE ORGANISMS. 421 



covering, under which is formed a weak cellulose membrane. 

 During this time the contents assume a red colour, and the en- 

 cysted Vampyrella finally appears in the form of the red capsule 

 with which the description of its life-history was commenced. 



The only other species of Vampyrella which it will be necessary 

 to refer to is one more recently described by Haeckel*, who dis- 

 covered it on the coast of Norway, and has assigned to it the 

 name of Vampyrella gompTionematis (fig. 12). It appears to live 

 exclusively on a species of OompJionema, whose cells it envelopes 

 and then sucks out their contents. 



On the branches of the Gomplionema (A) are occasionally found, 

 in place of the proper terminal cells of silica, a great abundance 

 of clear red spherical capsules (a). These are the cysts of the 

 Vampyrella. 



The free-creeping V. gomphonematis (B) always appears as an 

 irregular lump of protoplasm without nucleus or contractile 

 vesicle, while from its surface there are emitted a great number 

 of extremely fine pseudopodia. 



In this condition it creeps over the stems and branches of the 

 Gomphonema, adapting itself tO the form of its support ; and as 

 soon as it has reached one of the terminal siliceous cells of the 

 diatom, it extends itself over the entire cell so as completely to 

 envelope it in a thin layer of protoplasm. 



The plundering of the Gomphonema-ce]! now begins, and while 

 a number of fine pseudopodia radiate from the body of the 

 Vampyrella into the surrounding water, another portion of its pro- 

 toplasm forces its way between the siliceous plates of the cell into 

 the interior, and here appropriates the contents. 



The empty siliceous cell (A, g, Ji) of the Gomplionema is now 

 broken off" from its stem and, as foreign indigestible matter, is cast 

 out of the body of the Vampyrella, which continues to sit in the 

 place of the cell and there digests its food in quiet. In this way it 

 passes from cell to cell of the Gomphonema ; and when it has thas 

 plundered many cells, and by abundant nutriment has attained its 

 full size, it begins gradually to withdraw its pseudopodia to round 

 itself into a smooth, sphere of protoplasm, to encyst itself by the 

 exudation of a capsule, and pass into a resting state (a). 



The encysted Vampyrella continues now to sit on the summit 

 of the stem in the place of its last victim, and after remaining for 

 some time in this condition of repose, the contents of the capsule 

 * " Nachtrage zur Monograpbie der Monereu,'' Jeuaische Zeitschr. 1871. 



