1890.] The Evolution of Mind. 903 
tain that sensation resides in any but the cells of the nervous 
system, and if those of the peripheral parts of the system possess 
it, they do not retain it if they lose their connection with the central 
system. Now the cells of this system are the least modified of 
all those that constitute the soma of the metazoon, and thus 
they resemble most nearly the simple beings which constitute the 
lowest forms of the Protozoa. If they are capable of sensation 
in the one case they are likely to do so in the other. It appears 
that the conscious cell is the primitive cell, and the unconscious 
cell is the modified or specialized cell. And this conclusion coin- 
cides with what we know of the relation of consciousness to func- 
tion in the animals in which we can examine the history of both. 
Specialization of structure means specialization of function ; and 
specialization of function means accomplished education. Com- 
pleted education, as we have OR. seen, means unconsciousness, 
while ytothe beginnings of education, and 
to its successive steps up to completion. We are then led by the 
analogies of the education of tissues, as well as by their structure, 
to the belief in the presence of consciousness in the Protozoa. 
The demonstration of a sense analogous to sight in the Infusoria 
.by Klebs and Pouchet, and in the Ccelenterata by Romanes and 
Eimer, renders it unnecessary to pursue the argument further into 
the next higher type of the animal kingdom. 
Were the above reasons insufficient to lead us toour conclusion, 
a consideration of the movements of the Protozoa would do so. 
All authorities agfee that some of the actions of the Infusoria are 
in no sense automatic, but display a design as appropriate to the 
occasion as do those of the highest animals. The movements of 
the body of these animals are definitely directed towards their 
food or prey, and towards their opposite sex, and as definitely 
directed away from dangerous enemies. The movements of par- 
ticular parts of their bodies, as of their cilia and flagella, have 
definitely designed movements for special occasions. Some of 
the movements of the Amcebe have been, probably correctly, 
regarded as having a purely physical origin, due to the mobility 
of their protoplasm, and their contractility ; but others, such as the 
projection of pseudopodia towards food with which they are not 
