432 PROP. ALLMAN ON THE EECENT BESEAECHBS 



plasm issues through an aperture in one end of its siliceous 

 covering (E), contracts itself into a ball (F), begins to emit 

 radiating processes from its surface and to take in nourishment 

 from without, and then by a process of simple growth acquires 

 the condition of the adult Myxastrum. 



Under the name of MJyxodictyum sociale, Haeckel describes 

 another representative of the Monera, which he obtained from 

 the surface of the sea in the Bay of Algesiras. When taken it 

 consisted of a group of roundish masses of homogeneous proto- 

 plasm, resembling small Actinophryses, from each of which ra- 

 diated numerous fine branching and anastomosing filaments, which 

 became confluent with those of the neighbouring masses, uniting 

 the whole into a simple large plasma-net. 



The uniting filaments resembled in all respects the pseudopodia 

 of the true Ehizopoda, and the characteristic sarcode-currents 

 might be seen in them passing from mass to mass. Myocodictyum 

 would thus appear to represent a colony of Moners rather than a 

 single individual ; and Haeckel compares it in this respect with 

 the polycytarian or social Hadiolaria. 



Nothing decided has been discovered regarding the reproduc- 

 tion of Myxodictyum, but it is probable that some of the masses 

 detach themselves from the margin of the old colony and form 

 new ones. 



Those independent Amceha-like organisms which have neither 

 nucleus nor contractile vesicle, and whose body consists c " a per- 

 fectly structureless mass of protoplasm, have been, under the name 

 of Protamceia, separated by Haeckel from the true Amoehcs, which 

 always possess a nucleus and generally a vacuole, or even a true 

 contractile vesicle. 



Haeckel here describes his Prof a7noelaprimitiva(Qg. 16),whichhe 

 found among decaying leaves in the fine mud of a pond near Jena. 

 It consists of a mass of absolutely homogeneous protoplasm, which 

 emits from its periphery short blunt pseudopodia, and shows no 

 differentiation of a more firm outer and a softer inner portion, 

 as is seen in some other species of Protamoeha and in most, pro- 

 bably all, of the true Amoeba. It takes in nutriment by envelop- 

 ing solid matter in its substance in the manner of the true Amcebce 

 and fhe Amceha-like blood-cells of animals : and it multiplies by the 

 simplest form of non-sexual reproduction — the spontaneous divi- 

 sion of its body without previously passing into a resting state. 



Bodies entirely similar to these Protamcehce occur as transi- 



