PROTOPLASM AND NUCLEUS. 
41 
Myxomycetes, some swarm-cells, e.g. of Faucheria, allow the skin to be recognised, 
under sufficient magnifying power, as a hyaline edging ; in the swarm-cells of Faucheria 
it is evidently striated radially when seen in section, just as some cell-walls are ; 
Hofmeister (Handbuch, vol. L p. 25) found the same appearance in the plasmodia of 
.^thalium. Probably this skin is nothing but the pure basis of the protoplasm itself 
free from granules, of which the whole body is formed, but which is masked in 
the interior by grains and granules. It follows that in the amoeboid movements of 
Plasmodia the new extensions are always at first formed of the skin alone ; it is only 
G shows the further changes of the part c" in F. A a freshly escaped mass of protoplasm, rounded off into a sphere, the chlorophyll- 
granules lying all together in the inside ; a hyaline layer of protoplasm envelopes the whole as a skin. 
when they increase in size that the interior granular substance makes its appearance 
in them. This is more clearly the case in the masses of protoplasm that escape into 
water from the injured filaments of Faucheria, which often instantly become rounded 
into globular bodies, but not unfrequently show the amoeboid movement of plasmodia 
at a later stage ; they are somewhat longer, the full extremity of each being terminated by a knob ; 
as development proceeds the cilia become longer and the knobs become smaller in proportion to the 
increase in length, until the final hair-like form is reached. As long as the swaim-cell is in contact 
with the mother-cell-walls, the cilia are closely adpressed to the surface of the ectoplasm, with their 
apices directed forwards. The secretion of a cellulose envelope is closely and even inseparably con- 
nected with the presence of an ectoplasmic layer. See Strasburger, Studien über Protoplasma, Jena 
1876; Vines in Quart. Journ. Micr. Sei. 1877, pp. 124-132.] 
