190) CELL AND NUCLEAR DIVISION IN FULIGO VARIANS 235 
single nucleus of the vegetative body. The internal relations 
of nuclei and cytoplasm cannot be conceived as different, merely 
because in one case the nuclei and separate cytoplasmic masses 
were brought together by fusion, while in the other they were 
formed from a uninucleated cell by growth and nuclear division. 
Morphologically, however, the two structures must be re- 
garded as entirely distinct, and the possession of the plas- 
modium, and the capillitium formed as a deposit in vacuoles by 
the slime molds, is probably sufficient reason for regarding 
them as constituting a separate developmental series running 
back to an origin independent of any of the existing groups of 
alge or fungi. Sachs (18) has quite recently expressed the © 
opinion that they are to be classed with the fungi, but he brings 
ho morphological evidence to support his view. There can be 
fo question that the Acrasiez represent simpler forms out of 
which the Myxomycetes have developed, and we thus have a 
developmental series leading from simpler to more complex 
forms. The plasmodium and capillitium, appearing only in the 
oN specialized members of the group, are plainly secondarily 
acquired structures developed as additions to the structural 
features of the Acrasiez, and are not to be directly homologized 
208 Physiologically equivalent structures in other groups. 
muling Yological equivalence of the plasmodium and the 
: fe a. masses of protoplasm found in other fungi, such 
: where ( We. Pilobolus, etc., can hardly be questioned. , Else- 
i ‘multinuclesg ee discussed the question as to whether these 
_ ae ‘ Masses should be classed as single cells, or as ee 
of @ slime a isang tissues or organisms. The plasmodium 
On this Saas 53 well calculated to furnish further evidense 
amoeboid Ae n its method of origin by the fusion of distinct 
Jaen oo. it would seem to testify to its multiple 
in in an sea above, the whole physiology of the plas- 
nost oa reactions to stimuli, and growth, shows 
i fice a that it is a unit in exactly the same sense as 
; OF one of the swarm-spores which combined to 
' 
form it d 
ng fusing, the Swarm-spores gave up their individuality 
