336 
Labyriuthulca, especially of the simplest form of Navicula. 
But as the Diatomacese are also always (?) nucleated, and as, 
so far as they are known, they never appear as naked Plas- 
tides, their differences from the Monera are very decisive. 
V. Monera and Myxomycetes . 
Among all Protista, next to the true Rhizopoda, the Myxo- 
myceta stand nearest to the Monera. The colossal naked, 
freely moving sarcode bodies of Protogenes, Protomyxa, and 
also of Vampyrella, are not in themselves to be directly distin- 
guished from the plasmodia of the Myxomycetes, especially 
the semi-liquid forms. Only their further development allows 
us to perceive the divergence of the two groups. There is, 
in addition, the striking similarity of the reproduction by 
zoosjmres in Protomonas and Protomyxa. Hence these might 
be considered as the simplest Myxomycetes. But the spore of 
the Myxomyceta always encloses a nucleus, and is, therefore, 
a true cell, while in the Monera nuclei are never present. In 
this I recognise the substantial difference between the Monera 
and Myxomyceta, apart from the much higher differentiation 
of the sporangium in the latter. But one might consider the 
encapsuled resting condition of Protomyxa as the first and 
simplest commencement of the sporangium of the Myxomy- 
cetes. In both the zoospores pass over into the Amoeba con- 
dition. 
VI. Monera and Protoplasta. 
The Protoplasta, also, show, like the Myxomyceta and 
Rhizopoda, very close relations to the Monera. I have 
classed together as Protoplasta, in my f General Morphology,’ 
the three following groups of Protista : 
1. Gymnamocbae, the true, naked Amoeba?, with a nucleus, 
and with or without a contractile vesicle or vacuole ; Auta- 
mceba, Nuclearia, Pseudospora, Podostoma, Petalopus, &c. 
2. Lepamcebae (Amoeba? furnished with a shell or test ; 
Arcella, Difflugia, Euglyplia, &c.). 
3. Gregarina? (Monocystidea and Polycystidea). 
I regard the Gregarinae as Amoeba? which have degenerated 
by parasitism. The Monera show the closest affinities to the 
Protoplasta, especially to the Gymnamoeba?. Protamoeba is 
only to be distinguished from the true Amoebae (Autamceba) 
by the absence of a nucleus and of the contractile vesicles. 
The pseudo-navicella? of the Gregarinae remind us extremely, 
(still more than the “ spindles ” of the Labyrinthulea,) of the 
spindle-shaped spores of Myxastrum. But there is, again, an 
