26 
notwithstanding their composite character) in order to dispose of a difficulty 
which may perplex those, who have not followed closely the gradual change 
of opinion in respect to the constitution of cells ; and also because one 
German school formerly looked upon the lowest animals as unicellular 
organisms — whereas it is now accepted that the protoplasms of Monera are 
in their primary stage not so highly differentiated as the elements of a 
cell. 
The following is Hseckel's technical definition of the group Monera : 
' ' Organisms without organs, which in their perfectly developed condition 
form a freely-moving, naked, perfectly structureless, and homogeneous 
mass of sarcode (protoplasm). Nuclei are never differentiated in the homo- 
geneous protoplasm. Movement is effected by contraction of the 
homogeneous substance of the body, and by the protrusion of processes 
(pseudopods), varying in form, which either remain simple, or ramify and 
anastomose. Nutrition is effected in various ways, mostly after the 
manner of the Ehizopods. Reproduction is monogonous. Often, but not 
always, the freely-moving condition alternates with a state of rest, during 
which the body surrounds itself with an excreted structureless covering 
(encystation). All Monera live in water." 
Now, with this definition before us, we turn to Hseckel's table, and find 
as examples of Gymnoinonera — Protogenes and Protamceba, &c, which are 
animals living in water ; and of these animals Hseckel especially notes that 
they never pass into a resting condition nor become encysted. Consequently 
the Moner- Amoeba has a different life-history from that of the creatures 
discovered by Greef, and called by him land species of Amoeba. Herein 
I find support for the scruples formerly expressed by me in respect to 
naming all things Amoeboid which shew the phenomenon of a simple con- 
tractility. We know that various pseudo-cells, or non-nucleated lumps of 
plasma manifest this property (e. g. the white blood-cells of animals 
generally, cells found in the seminiferous tubes, and a great variety of other 
pseudo-cells, such as the Amoeboid germs of Gregarinse, &c,) In short, it 
is becoming universally accepted that the contractility of the Amoeba, as 
observed in the typical Amoeba princeps, is not a special character of this 
creature, but a primal condition or property of the fundamental protoplasm 
from which all animals begin. 
According to Hseckel's definition, the Amoeba, such as we know it, (that 
is, a nucleated but naked plasm with vacuoles) belongs to his 8th group of 
Amoeboid Protoplasts, and the Land Amoeba of Greef is a still higher 
organism, to be raised altogether above the kingdom of Protista, by the 
