. General physiology; an outline of the science of life. 432 GENERAL PHYSIOLOGY whole series of substances of non-bacterial origin. Thus, Buchner found that broth made of wheat flour and that made of pea flour possess especially strong chemotactic power. Finalty, Sicherer ('96) has recently shown that under proper conditions the leucocytes of warm-blooded animals outside the body exhibit their chemo- tactic properties toward very varied substances for a long time, as clearly as in the living body itself The chemotaxis of leucocytes plays an important rule in the development of many animals. Th
. General physiology; an outline of the science of life. 432 GENERAL PHYSIOLOGY whole series of substances of non-bacterial origin. Thus, Buchner found that broth made of wheat flour and that made of pea flour possess especially strong chemotactic power. Finalty, Sicherer ('96) has recently shown that under proper conditions the leucocytes of warm-blooded animals outside the body exhibit their chemo- tactic properties toward very varied substances for a long time, as clearly as in the living body itself The chemotaxis of leucocytes plays an important rule in the development of many animals. This is made clear especially by the beautiful investigations of Kowalevsky ('87) upon insects. When the fly-larva changes into the complete fly—a metamor- phosis that takes place fairly rapidly—the organs of the larval body, such as the creeping muscles, become superfluous, and. Fig. 200.—Leucocytes destroying the muscles in the metamorphosis of the larva of the fly. Tlio granular masses are leucocytes, the striped masses bits of muscle. (After Kowalevsky.) begin to degenerate. The substances formed at the beginning of this degeneration have a strong chemotactic action upon the leucocytes; the latter wander into the degenerating organs in great crowds, and as genuine phagocytes devour the disintegrating masses, and thus accelerate their removal (Fig. 209). It is charac- teristic that the phagocytes manifest their activity only in insects in which the metamorphosis takes place very rapidly; but that in others, as in the moth, and in the degeneration of the tail of the tadpole, they have no share. Nevertheless, Metschnikofi^ was able to demonstrate analogous phenomena in the development of star-fishes. Chemotaxis is wide-spread in the flagellate Bacteria,Infuso7-ia,and swarm-spores. In Bacteria the phenomenon was first disco\-ered by Engehnann ('81, 1 ; '94), and was at once employed practically. Please note that these images are extracted from scanned page images that may h
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