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may be better expressed in the statement that tbe higher Protozoa 
may be regarded as organisms of fundamentally Protomyxoid form- 
history, in which, however, some one phase has attained compara- 
tively high specialisation and differentiation, together with relatively 
greater permanence. Or the same idea may be stated in the exactly 
converse way, that the Protozoa may be viewed as organisms of 
fundamentally Protomyxoid form-history, in which, however, one, 
two, or three of the phases become abbreviated into merely em- 
bryonic ones, or may even (by that shortening of development with 
which embryologists are so familiar in the higher organism) become 
completely suppressed. 
Thus then, if illustration be needed, a Heliozoon differs from 
Protomyxa merely * in tbe higher differentiation and relative per- 
manence of the amoeboid phase of its life-cycle, since more or less 
brief encysted, ciliated, and plasmodial phases have all been observed. 
The more specialised but kindred Eadiolarian seems to have lost its 
plasmodial phase ; so too, perhaps, has the monad, while in the 
Gregarine only the ciliated state is wanting. 
2. Affinities of the Protophyta . — Passing now to the second 
problem proposed at the outset, that of the affinities of the Proto- 
phytes, the same conception may be at once applied. Too much 
importance is here attached to the encysted phase, for the life-cycle 
is clearly apparent in many forms. Treviranus, in 1811, made the 
notable discovery that the spores of Confervse move like Infusoria, f 
Many years later Unger described the same phenomena in Vaucheria 
clavata, as “the plant in the moment of transition to the animal,” J 
while Von Siebold and others argued against this essentially just 
view, with more ingenuity than soundness. The wide prevalence 
of this change is constantly being confirmed. Uot only have we 
a thoroughly well-defined and constant cycle between the resting 
and the ciliated sbate, but we may fairly reckon the brief phase of 
inactivity, which so often is observable between the loss of cilia and 
the return to the encysted state (when the organism closely resembles 
* The possession or non-possession of a nucleus is of course immaterial, so 
far as the form-history is concerned. 
t Treviranus, Beitr. z. Pfl. Physiol., Gott. 1811, p. 78. 
J Unger, Die Pflmize in Momente d. Thierwendung , Wien, 1843. Siebold, 
Dissert, de ffnibus int. reg. an. et reg. constit, Erlangen, 1844. 
