THE MYXOMYCETES OR MYCETOZOA ; ANIMALS OR PLANTS? 101 
the ‘ plasmodium. ’ This plasmodium, taking the form of either 
a colossal Amoeba, or other Bliizopod, in addition to possessing 
locomotive faculties and the capacity of ingesting solid food, he 
further showed to exhibit, in its more extended, ramified con- 
dition, a distinct circulation or cyclosis of its internal granular 
elements. Embodying the results of Cienkowski’s investiga- 
tions with those of his own earlier and more recent researches, 
De Bary published, in the year 1864, his more extensive account 
of the Mycetozoa,* which up to the present date is accepted as 
representing the most complete record extant of the life 
phenomena of these remarkable organisms. While still in- 
cluded among the Fungi, perhaps for convenience sake, by 
systematic botanists, their exceedingly anomalous plan of 
structure and development has in most instances been fully 
recognized. No more fitting illustration of the estimate ac- 
corded to them by this class of biologists is perhaps to be found 
than the general account of the group included in Julius Sachs’ 
Textbook of Botany ^ herewith reproduced in extenso : — 
‘ The Myxomycetes include a numerous group of organisms 
which in many respects differ widely from all other vegetable 
structures, but in the mode of formation of their spores stand 
nearest to the Fungi, on which account we may treat them as a 
supplement to that class. The Myxomycetes are remarkable in 
no ordinary degree from the fact that during the period of their 
vegetation and assimilation of food they do not form cells or 
tissues. The protoplasm, which in all other plants is also the 
general motive power of the phenomena of life, remains in them 
during the whole of this period perfectly free, collects into 
considerable masses, and assumes various shapes from the in- 
ternal force residing in it without becoming divided into small 
portions which surround themselves with cell- walls, or become 
cells. It is only when the protoplasm passes into a condition of 
rest in consequence of being surrounded by unfavourable condi- 
tions, or when it concludes its period of vegetation by the 
formation of the reproductive organs — its internal and ex- 
ternal movements ceasing at the same time — that it breaks up 
into small portions which surround themselves with cell-walls, 
and which even then never form a tissue in the proper sense of 
the term. The Myxomycetes live upon decaying and rotting 
vegetable substances. While endowed with motion, they either 
creep over the surface of the substratum or live in hollows and 
pores in its interior, but for the purpose of reproduction they 
always come to the surface. When entering on the repro- 
* Die Mycetozoen ein Beitrag zur Kenntniss der niedersten Organismen. 
Leipzig, 1864. 
t English edition, translated by A. W. Bennett and W. T. Dyer. 
London. 1875. 
