A text-book of general bacteriology / by Edwin O. Jordan.

  • Jordan, Edwin O. (Edwin Oakes), 1866-1936.
Date:
1912
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of general bacteriology / by Edwin O. Jordan. Source: Wellcome Collection.

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    of prey darts through the sea; they were found everywhere, although not in large numbers. A second kind was similar to that marked B (Fig. 1). These sometimes spun around in a circle like a top, and sometimes described a path like that shown in C-D (Fig. 1); they were present in larger numbers. A third kind could not be distinguished so clearly; now they appeared oblong, now quite round. They were so very small that they did not seem larger than the bodies marked E, and besides they moved so rapidly that they were continually running into one another: they looked like a swarm of gnats or flies dancing about together. I had the impression that I was looking at several thousands in a given part of the water or saliva mixed with a particle of the material from the teeth no larger than a grain of sand, even when only one part of the material was added to nine parts of water or saliva. Further, the greater part of the material consisted of an extraordinary number of rods, of widely different lengths, but of the same diameter. Some were curved, some straight, as is shown in F; they lay irregularly and were interlaced. Since I had previously seen living animalcules of this same kind in water, I endeavored to observe whether there was life in them, but in none did I see the smallest move¬ ment that might be taken as a sign of life.” Leeuwenhoek supple¬ mented his observations with drawings, and there is no doubt that he was the first to see bacteria and describe them accurately. The Origin of Bacteriology.—Leeuwenhoek’s observations remained practically isolated and without fruit for nearly a cen¬ tury. It was not until 1786 that the work of the Danish zoologist,. O. F. Muller, added anything of importance to the knowledge of bacteria. Muller recognized clearly the difficulties of studying such minute organisms. “The difficulties,” he writes, in words that still appeal to the modern bacteriologist, “that beset the investigators of these microscopic animals are countless; the sure and definite determination [of species] requires so much time, so much acumen of eye and judgment, so much perseverance and practice, that there is hardly anything else so difficult.” Despite the obstacles, how- Fig. 1.—The first pic¬ torial representation of bacteria. Leeuwenhoek, 1683 (Loffler).