THE MONERA. 75 



tinct from one another, their margins arc clear and transpar- 

 ent, and the granules which they may contain plainly Mow 

 into their interior from the more fluid central part of the 

 body. But, when they are filiform, they are very apt to run 

 into one another, and give rise to networks, the constituent 

 filaments of which, however, readily separate and regain their 

 previous form ; and, whether they do this or not, the surfaces 

 of these pseudopodia are often beset by minute granules, 

 which are in incessant motion — like those which are observ- 

 able on the reticulations of the protoplasm of the cells in a 

 Tradescantia hair. 



The myxopod thus described moves about by means of its 

 contractile pseudopodia, and takes the solid matters which 

 serve as its food into all parts of its body by their aid ; while 

 the undigested exuvia of the food are rejected from all parts 

 of the body in the same indiscriminate way. It is an organ- 

 ism which is devoid of any visible organs except pseudopodia; 

 and, so far as is known at present, it multiplies by simple di- 

 vision. 



The Protamoeha (with lobate pseudopodia) and Protoge- 

 nes (with filamentous pseudopodia), of Haeckel, are Monera 

 of thisextrem3ly simple character. In Myxodictyum (Haeck- 

 el) the pseudopodia of a number of such 3Ionera run togeth- 

 er, and give rise to a complex network, or common plasmo- 

 dlam. 



It is open to doubt, however, whether either Protamoeha, 

 Protogenes, or Myxodictyum^ is anything but one stage of a 

 cycle of forms, which are more completely, though perhaps 

 nob yet wholly, represented by some other very interesting 

 Monera, also described by Haeckel. 



Thus, the genus Yampyrella is a myxopod with filamen- 

 tous pseudopodia, a species of which infests one of the stalked 

 Diatomace:^, Gomphonema, feeding upon the soft parts of the 

 frustules of its host, by inserting some of its pseudopodia 

 through the raphe of the frustule, which it envelops, and 

 absorbing the contained protoplasm. Having thus provided 

 itself with abundant nourishment, by creeping from frustule 

 to frustule of the Gomp>honema, it thrusts aside the last 

 evacuated frustule from its peduncle, and, taking its place, 

 draws in its pseudopodia, becomes spherical, and surrounds 

 itself with a structureless cyst, inclosed in which it remains 

 perched upon the peduncle of the Gomplionema. Soon its 

 protoplasm undergoes division into four equal masses, and 

 each of these, becoming converted into a young Vainpyrella, 



