LIVING AND LIFELESS MATTER. 81 
ear, nose, tongue, and the entire surface of the body—are faith- 
ful reporters of facts. They put the inner and outer worlds in 
communication, and without them all higher life at least must 
cease, for the organism, like a train directed by a conductor that 
disregards the danger-signals, must work its own destruction. 
Without going into further details, suffice it to say that the pro- 
cesses of the various cells are subordinated to the general good 
through the nervous system, and that susceptibility of proto- 
plasm to stimuli of a delicate kind which enables each cell to 
adapt to its surroundings, including the influence of remote as 
well as neighboring cells. Without this there could be no 
marked advance in organisms, no differentiation of a pro- 
nounced character, and so none of that physiological division 
of labor which will be inferred from our brief description of 
the functions of a mammal. The whole of physiology but 
illustrates this division of labor. 
It is hoped that the above account of the working of the 
animal body, brief as it is, may serve to show the connection of 
one part functionally with another, for it is much more impor- 
tant that this. should be kept in mind throughout, than that all 
the details of any one function should be known. 
LIVING AND LIFELESS MATTER. 
In order to enable the student the better to realize the na- 
ture of living matter or protoplasm, and to render clearer 
the distinction between the forms that belong to the organic 
and inorganic worlds respectively, we shall make some com- 
parisons in detail which it is hoped may accomplish this ob- 
ject. 
A modern watch that keeps correct time must be regarded 
as a wonderful object, a marvelous triumph of human skill. 
That it has aroused the awe of savages, and been mistaken for 
a living being, is not surprising. But, admirable as is the 
result attained by the mechanism of a watch, it is, after all, 
composed of but a few metals, etc., chiefly in fact of two, brass 
and steel; these are, however, made up into a great number 
of different parts, so adapted to one another as to work in 
unison and accomplish the desired object of indicating the time 
of day. 
Now, however well constructed the watch may be, there are | 
‘waste, wear and tear, which will manifest themselves more and 
