29 
tinually changing, globularly contracted when at rest. Our 
sharpest discrimination can detect no trace of an internal 
structure, or of a formation from dissimilar parts. As the 
homogeneous, albuminous mass of the body of the Moner 
does not even exhibit a differentiation into an inner nucleus 
and an outer plasma, and as, moreover, the whole body 
consists of a homogeneous plasma, or protoplasma, the organic 
matter here does not even reach the importance of the sim- 
plest cell. It remains in the lowest imaginable grade of 
organic individuality, as that of one of the simplest of the 
Gymnocytodes. 
The question which has been so often debated during the 
last twenty years as to a boundary between the animal and 
vegetable kingdoms will be decided by the Monera, or, more 
correctly, they will prove that a perfect separation of both 
kingdoms, in the manner in which it is usually attempted, 
is impossible. The Monera are apparently such peculiar or- 
ganisms that they can be classed with equal propriety, or 
rather with equal arbitrariness, as primitive animals or as 
primitive plants. They may just as well be regarded as the 
first beginnings of animal as of vegetable organization. 
But as no one mark of distinction inclines them more to 
one side than to the other it seems most correct at present to 
class them as intermediate between true animals and true 
plants ; and to assign them with the Rliizopoda, Amoebae, 
Diatomaceae, Flagellata, &c., to that ill-defined kingdom be- 
tween the animal and vegetable kingdoms which I have 
called the kingdom of primitive forms, or Protista . 1 
The Monera are indeed Protista. They are neither ani- 
mals nor plants. They are organisms of the most primitive 
kind : among which the distinction between animals and 
plants does not yet exist. But the term “ organism ” itself 
seems scarcely applicable to these simplest forms of life ; for 
in the whole conception of the “ organism ” is especially im- 
plied the construction of the whole from dissimilar parts, — 
from organs or limbs. At least, two separate parts must 
be united to complete the description of a body as an organ- 
ism in this original sense. Every true Amoeba, every true 
(i. e., nucleus-including) animal and vegetable cell, every 
animal-egg, is, in this sense, already an elementary organ- 
ism, composed of two different organs, the inner nucleus 
and the outer cell-matter (Plasma or Protoplasma). Com- 
pared with these last the Monera are strictly “ organisms 
without organs.” Only in a physiological sense can we still 
1 to TrpwTHTTov, the first of all, primordial. * Geuerelle Morphologie,’ 
vol. i, pp. 203, 215 ; vol. ii, p. xx. 
