1885. ] Comparative Physiology and Psychology. 5 
thrive, instance this. With differentiation and higher organiza- 
tion comes the increased necessity for stability of environment, 
paralleled by the ability of low forms to reproduce lost members, 
not evident in developed life. 
We may regard the Amceba in many ways as having under- 
gone development above some lower form; but pending the set- 
tlement of the bathybius question, and with a mere glance at 
Protista and preameebic life, the organism affords us a convenient 
starting point for inquiry. While physiologists agree in its pos- 
session of the fundamental activities of life in simplest modes of 
manifestation, they usually content themselves with a mention of 
this fact and proceed to examine complex differentiated tissues as 
though the Amceba merited no further attention. From my way 
of looking at it, the Amceba, containing the solution of so much, 
deserves very deep consideration, which being accorded it, the 
apparently simple becomes intricately complex in that it explains 
so much. 
First the environment of the Amceba: Stagnant water, mud or 
damp earth, or from the infusion of any animal substance in water 
and allowing it to evaporate while exposed to direct sunlight.’ 
It absorbs oxygen and gives out CO, 45° C. and strong 
shocks of electricity kill it; moderate shocks of electricity causes 
it to assume the globular still form. Crushing kills it and then 
even the nucleus disappears. Freezing point arrests motions. In 
its surroundings there are, besides its food, air, water, mineral mats 
ter, sunlight, heat and cold, mechanical vibrations. | 
At 35° heat stiffens it, at once proving the development of the 
Ameceba for its medium, and that of the white blood corpuscle, 
which is more sluggish, for a different one, the temperature of 
the blood currents of the different animals. This may be re- 
garded as an acquired adjustment. 
Its molecules are subject to the law of gravitation. Light 
attracts it; heat increases, within limits, its activity; vibrations, 
such as eddies of its medium, move it; electricity stuns it; its 
intimate structure assimilates, chemically, the substances for 
which its molecules have affinities, and being nonresponsive to 
those for which it has not, consigns them to the exterior. 
Now if all these forces act upon and in the Ameeba, what is to 
prevent external forces from pulling or pushing out its pseudo- 
Practical Biology, Huxley and Martin. 
