The Mechanistic Conception of Life; Biological Essays (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1912 Excerpt: ...when put back into normal sea-water. A small number of eggs divided into two or four cells, and, in a few cases, went as far as about sixty cells, but no larvae ever developed from these eggs. Morgan2 had used the same concentration of sea-water as Norman3 and I had used in our previous experiments. I had added about 2 grams of sodium chloride to 100 c.c. of sea-water. Norman used instead of this 3 grams of MgCl2 to 100 c.c. of sea-water, and Morgan used the same concentration. Mead4 made an observation somewhat similar to Morgan's upon Chaetopterus. He found that by adding a very small amount of KCl to sea-water he could force the unfertilized eggs of Chaetopterus to throw out their polar bodies. The substitution of a little NaCl for KCl did not have the same effect. While continuing my studies on the effects of salts upon life phenomena, I was led to the fact that the peculiar actions of protoplasm are influenced to a great extent by the ions contained in the solutions which surround the cells. As is well known, if we have a salt in solution, e.g., sodium chloride, we have not only NaCl molecules in solution, but a certain number of NaCl molecules are split up into Na ions (Na atoms charged with a certain quantity of positive electricity) and Cl ions (Cl atoms charged with the same amount of negative electricity). When an egg is in sea-water, the various ions enter it in proportions determined by their osmotic pressure and the permeability of the protoplasm. It is probable that some of these ions are able to combine with the proteins of the protoplasm. At any rate, the physical qualities of the proteins of the protoplasm (their state of matter and power of binding water) are determined by the relative proportions of the various ions present in the protopl...