30 
call them organisms ; as individual portions of organic mat- 
ter, which fulfil the essential life-functions of all organisms, 
nourishment, growth, and reproduction. But all these dif- 
ferent functions are not yet limited to different parts. They 
are all still executed equally by every part of the body. If 
the natural history of the Monera is already, on these 
grounds, of the highest interest as well for morphology as 
for physiology, this interest will be still more increased by 
the extraordinary importance which these very simple or- 
ganisms possess for the important doctrine of spontaneous 
generation, or archegony. I have shown in my ‘ General 
Morphology ’ that the acceptation of a genuine arche- 
gony (once or repeated) has at present become a logical 
postulate of scientific natural history. Most naturalists who 
have discussed this question rationally believed that they 
must designate simple cells as the simplest organism pro- 
duced thereby, from which all others developed them- 
selves. But every true cell already shows a division into two 
different parts, i. e., nucleus and plasma. The immediate 
production of such an object from spontaneous genera- 
tion is obviously only conceivable with difficulty ; but it is 
much easier to conceive of the production of an entirely 
homogeneous, organic substance, such as the structureless 
albumen-body of the Monera. 
On these grounds, and on others to be hereafter discussed, 
it seems well at the present time, now we are just at the 
beginning of our knowledge of these very interesting pri- 
mordial forms, to put together everything known about 
them. I received the first impulse to attempt this 
monograph from a series of new observations on some 
hitherto unknown Monera, which I had an opportunity of 
making, in the winter of 1866 — 1867, on the coast of 
Lanzarote, one of the Canary Islands. Before detailing these 
observations, I think it advisable to give a short, historical 
sketch of the certain information hitherto published concern- 
ing Monera. I may also mention that I restrict myself entirely 
to true Monera, i. e., to naked Plasma-bodies without nuclei, 
or essential organs ; and that I shall pay no regard to the 
Protoplasta, distinguished by the possessions of one or more 
nuclei (Amoebae, Arcellae, &c.) : nor to the Bhizopoda, Sipho- 
nea, &c., distinguished from these latter by a distinct shell 
or membrane. 
The first Moner whose natural history was fully investigated 
was Protogenes primordiulis / which I observed, in the spring 
'Ernst Haeckel, “On the Sarcode Bodies of the Rhizopoda;” ‘Zeit- 
schrift fur wissensch. Zoologie,’ 1865, xv Bd., p. 360, Taf. xxvi, fig. 12. 
