AMONG SIMPLE SAECODE OEaANISMS. 429 



with one another, radiate in all directions. Nutriment is ingested 

 in the same manner as by the true Rhizopoda, and reproduction 

 is effected by a simple spontaneous division of the body into two 

 halves without this phenomenon being preceded, as in other cases, 

 by a motionless or encysted state. 



In the present memoir Haeckel describes several genera of 

 Monera. The Protomyxa, of which we know only one species, 

 P. aurantiaca (fig. 14), was found on an empty Spirula-%\x&M in the 

 Canary Islands. In its developed state (F) it forms minute stellar 

 and arborescent figures of an orange-red colour, which spread over 

 the surface of the shell and vividly remind us of the ramified con- 

 tractile pigment-cells common in the skin of Amphibia and 

 Fishes. Each star-like body presents a central mass of sarcode 

 from which radiate numerous branches, which subdivide and in- 

 osculate and form a beautiful moving and changeable net of pro- 

 toplasm not unlike that of the Myxomycetse. Orange-red gra- 

 nules, to which the colour of the plasma is due, streamed in all 

 directions through the sarcode-net. Foreign bodies also, such as 

 pelagic Infusoria and Diatomacese, were seized by the protoplasm 

 and engulfed as food in its substance, where they might be seen, 

 along with the red granules, to be carried away in its currents. 



No nucleus or definite contractile vesicle was present, though 

 numerous floating and inconstant vacuoles were dispersed through 

 its substance. 



After a time an important change begins to take place. The 

 currents become slower, the ramified processes become gradually 

 withdrawn ; and after the siliceous and other indigestible remains 

 of the food are ejected, the whole body becomes rounded into a 

 spherical mass. Eound this a transparent cyst now becomes 

 excreted, and the Protomyxa passes into a state of complete qui- 

 escence (A). These motionless encysted balls of orange-red proto- 

 plasm were also observed by Haeckel attached to the surface of 

 the /S^z>w?a-shel], and their subsequent history was followed by 

 him. 



He found that after a time the contents of the cyst became 

 slightly retracted from the walls, and then became broken up 

 into a multitude of small, round, structureless, naked balls (B). 

 After remaining in this condition unchanged for several days, 

 the contained balls began to move within the cyst ; and as the 

 motion became more lively, the balls assumed a pyriform shape, 

 in which one end was drawn out into a fine point. Soon after this 



