253 
object, and consider them from the point of view of the cell 
theory and of the protoplasm theory. 
Professor Ernst Haeckel! has made, in these last few 
years, a discovery of great importance, in demonstrating the 
existence of a whole series of lower organisms, devoid of all 
organisation, of all appreciable structure, of all determinate 
form. In all phases of existence they consist of simple 
little masses of protoplasm, without any membrane, and 
without any nucleus. He has formed them into a special 
group, which he has called the group of the Monera. These 
beings are not only the simplest organisms known, but they 
are the most simple beings which one can imagine. ‘Their 
existence demonstrates that there are beings to be met with 
simpler than the monocellular organisms. In fact, the Monera 
are not cells; life manifests itself in small masses of albu- 
minoid material, without form and without organisation. 
One cannot distinguish in them any differentiation of parts, 
any organ, any trace of nucleus. Cienkowski* had observed 
and described, nearly at the same time as Haeckel, organisms 
of this group—the Protomonas and Vampyrella; but it is 
Haeckel who first demonstrated that it is necessary to sepa- 
rate these organisms from all the groups hitherto known ; 
it is he who has demonstrated their extreme importance 
from the point of view of general morphology ; it is he who 
has proposed to constitute the group of Monera, and who has 
made known the greater part of the creatures belonging to 
this group. 
The Monera, not being cells, Haeckel proposes to distin- 
guish them, histologically, under the name of Cytods, and he 
distinguishes the Gymnocytods and the Leptocytods accord- 
ing as these little living masses are devoid of or provided 
with an enveloping membrane. 
The substance which constitutes these organisms is identi- 
eal, as far as its physical characters are concerned, with the 
sarcode of the Rhizopods ; this is itself nothing more than that 
protoplasm which one finds in every living organic element, 
cell, or cytod, whether belonging to a protiston, a plant, or an 
animal. 
From the chemical point of view there ought to be a 
difference between the protoplasm of the Monera and Cytods 
generally and the protoplasm of cells. The sarcode of the 
1 EK. Haeckel, “ Der Sarcode Korper der ered age ‘Zeitschrift fiir 
— Zool.,’? 1865, Bd. xv. ‘Generelle Morphologie der Organismen,’ 
3 Cienkowski, ‘Beitrage zur Kenntniss der Monaden;’? Max Schultze’s 
* Archiv fiir Mikr. Anat.,’ 1865, t. i. 
