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That is, one cell specializes, let us say, in secretion, another in contractility, another in receiving and carrying stimuli, etc.
The lowest plant, or animalcule, feeds, grows, and reproduces its kind. In addition, all animals manifest those transitory changes of form which we class under irritability and contractility; and, it is more than probable, that when the vegetable world is thoroughly explored, we shall find all plants in possession of the same powers, at one time or other of their existence.
The proper procedure in these circumstances is first properly to reduce the blood pressure, or what I have, quoting Hare, ventured to call the over plus pressure. The relation of osmosis, lymphagogue activity, absorption of edema, capillary contractility and decreased affinity of ocular colloids for water to the reduction of increased intra-ocular tension.
There are some to whom living protoplasm is a substance, even such as Harvey conceived the blood to be, "summa cum providentia et intellectu in finem certum agens, quasi ratiocinio quodam;" and who look with as little favour as Bichat did, upon any attempt to apply the principles and the methods of physics and chemistry to the investigation of the vital processes of growth, metabolism, and contractility.
And, so far as the conditions of the manifestation of the phænomena of contractility have yet been studied, they are the same for the plant as for the animal. Heat and electric shocks influence both, and in the same way, though it may be in different degrees.
Among the lower plants, it is the rule rather than the exception, that contractility should be still more openly manifested at some periods of their existence.
Thus that greater impressibility and contractility, which in the rudest animal types characterize the units of the ectoderm, characterize also the units of the primitive social stratum which controls and fights; since impressibility and contractility are the respective roots of intelligence and strength.
The protoplasm of Algae and Fungi becomes, under many circumstances, partially, or completely, freed from its woody case, and exhibits movements of its whole mass, or is propelled by the contractility of one, or more, hair-like prolongations of its body, which are called vibratile cilia.
And, so far as the conditions of the manifestation of the phenomena of contractility have yet been studied, they are the same for the plant as for the animal. Heat and electric shocks influence both, and in the same way, though it may be in different degrees.
And not only was this gradually discovered, but it was found that these semifluid contents of the plant cell had, in many cases, a remarkable power of contractility quite like that of the substance of animals.
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