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membrane, but went on, and this, Haeckel observes, ‘ would be 
better conceived as a germ -formation than as a process of division 
or gemmation! Still later, some of the smaller or contained 
balls became pear-shaped and moved actively about when the 
cell-membrane burst, their movements being accelerated as 
soon as they were free. (Fig. 8, e!) Ultimately, * the pear- 
shaped tail-bearing germs, or rather germ cy tods’ (whatever 
that may mean), assumed an Amoeboid condition (Fig. 8, /), 
which Haeckel again declares was structureless throughout, and 
( thereby the morphological status of the simplest conceivable 
organic individual was that of a naked cytode or gymno- 
cytode.’ 
4 Myxastrum radians ’ (Plate iv. fig. 9), at first reminded 
Haeckel of l Actinosph cerium Eichhornii ,’ inasmuch as it consisted 
of a small globular mass of structureless , homogeneous jelly, 
covered with the radiating pseudopodia of Actinophrys. The 
central or inner mass consisted of a sarcode body which con- 
tained very numerous interspersed, bright, shining particles, 
and a small number of larger strongly-refracting granules. 
Myxastrum is distinguished from Actinosphcerium by the absence 
of vacuoles, nucleus-holding cells, and any difference between 
its outer and inner portions, the whole mass being homogeneous. 
On this ground it might rather be associated with Actinophrys 
Sol. But, again, it does not possess the contractile vesicle of 
the latter, ‘ and is especially distinguished by its peculiar repro- 
duction! Haeckel attempts to account for the granules by 
regarding them as ‘ the products of a change of substance , it 
being extremely probable that they are assimilated substances 
produced by the chemical action of the digestive sarcode upon 
the food taken, and are afterwards changed again into sarcode.’ 
This is supposed to be proved by the increase or diminution in 
the number of the granules which were observable, as the crea- 
tures, whilst under observation, were either fed upon generous 
diet, or starved. After a time the small globular mass of jelly 
constituting the body of Myxastrum became encysted like Pro- 
tom yxa (Fig. 10), the cyst-membrane becoming thicker and 
thicker by the addition of fresh concentric layers, and finally 
reached a thickness amounting to an eighth of the diameter of 
the entire mass. After the lapse of a fortnight the contents 
were developed into a number of spindle-shaped bodies (Figs. 
11 and 12), which subsequently became oblong and covered 
by a thin wall having a well-defined double outline, which was 
proved to consist of silex (Fig. 13). Ultimately, the siliceous wall 
of each of these bodies burst at one extremity, and gave egress 
to minute spherules — 4 sporangia’ (Fig. 14) — which finally took 
the parent form of Myxastrum. 
Here, then, we have presented to us the clearest proof that 
