The mechanistic conception of life : biological essays by Loeb Jacques 1859-1924

Author:Loeb, Jacques, 1859-1924 [Loeb, Jacques, 1859-1924]
Language: eng
Format: mobi
Tags: Life (Biology), Biology -- Philosophy, Biology, Mechanism (Philosophy)
Publisher: Chicago, Ill. : University of Chicago Press
Published: 1912-03-03T05:00:00+00:00

122 The Mechanistic Conception of Life

In this case it was shown, that although these eggs received the same sea-water as the ones which developed, and although they were injured less than the ones which developed, yet not one single egg formed a membrane or reached the blastula stage. If the sea-water had contained any spermatozoa these eggs should have reached the blastula stage.^ Hence, as in nine different series of experiments these results were confirmed, we may assume that by treating the eggs for two hours with a solution of equal parts of a ^ n MgCl, solution and sea-water we can cause them to develop parthenogenetically into plutei.

Ill

What conclusions may we draw from these results ? If we wish to avoid wild and sterile speculations, I think we should confine ourselves to the following question: What alterations can be produced in an egg by treating it for two hours with a solution of equal parts of ^^n MgClg and of sea-water ? Even in this regard we can only give a very indefinite answer which, however, will have to be in the following direction: The bulk of our protoplasm consists of colloidal substances. This material easily changes its state of matter and its power of binding water. It seems probable that changes of these two qualities are mainly responsible for muscular contraction and perhaps amoeboid motions. Among the agencies that cause changes of these physical qualities we know of three that are especially powerful. The one is specific enzymes (trypsine, plasmase, etc.). The second is ions in definite concentration. The concentration varies for various ions. The third agency is temperature. In our experiments it is obvious that only the second possibility can have been active. I do not consider it advisable to enter into theoretical discussions beyond these

1 Through other control experiments I convinced myself that a treatment of eggs or spermatozoa with equal parts of a -g'^n MgClg solution and sea-water diminishes the impregnability of the eggs and annihilates the fertilizing power of spermatozoa in a very short time.

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