Mind in Nature: Or The Origin of Life, and the Mode of Development of Animals |
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abdominal animals aperture appear aquiferous Articulata Bacteriums bilaterality body branches Bryozoa budding canal cells character cilia circle circulatory system contractile vesicle corresponds creature degree diagrams diam Difflugia digestive cavity disc distinct edge elongated embryo Epistylis Euglena feelers figure flasks fluid ganglion germinal germinal vesicle globular grand division head heart Hydra individual infusorian intestine joints kinds Lancelet latter layer longitudinal lower side lowest mass median minute Mollusca mouth naturalists nature nerve nervous collar nervous cord nervous system oblique Original pair Paramecium passes plant Pleuronema posterior end proboscis Protozoa pseudopodia relation reproductive organ resemblance right and left self-division shell spiral spores stage starfish stem Stentor stomach tail Tardigrades tentacles throat tion transparent transverse Trepangs tube upper vertebral Vertebrata vessels vibratile cilia vibrating Vibrios Volvox whilst worms yolk young Zoöphytes zoospores
Popular passages
Page 96 - Agassiz. I simply placed the preparations before him, and, without giving him the least hint of the origin of the muscle, I was pleased to have him rediscover what I had seen but fifteen minutes before. The number of ultimate cellules in a moving string varied from two to fifty ; the greatest number of strings were composed of only three or four, often six to eight, and rarely as high as fifty. Very rarely the fibres split longitudinally, and in such instances the fibrillae were most frequently long,...
Page 98 - Amelia flavtdula, our common jelly-fish, I observed that the whole component mass of cells was in violent agitation, each cell dancing zigzag about within the plane of the wall. If any one will shake about a single layer of shot in a flat pan, he can obtain an approximate idea of the appearance of this moving mass. In a perfectly healthy condition, these cells lie closely side by side, and do...
Page 23 - If, on the one hand, it is urged that all organisms, in so far as the early history of them is known, are derived from ova, and, therefore, from analogy, we must ascribe a similar origin to these minute beings whose early history we do not know, it may be urged with equal force, on the other hand, that all ova and spores, in so far as we know anything about them, are destroyed by prolonged boiling ; therefore from analogy we are equally bound to infer that Vibrios, Bacteriums...
Page 96 - ... same optical properties as the latter. Some of these appeared to be attached to the ends of the flat, ribbon-like fibres, and others at times loosened themselves and swam away. I was immediately impressed with the daring thought, that these vibrios were the...
Page 22 - ... be said to be of rare occurrence. We have not in any instance detected dried animalcules which were resuscitated by moisture, and when the dust has been macerated in water none have appeared until several days afterwards, until after a lapse of time when they would ordinarily appear in any organic solution. Those who advocate the theory of spontaneous generation, on the other hand, will doubtless find, in the experiments here recorded, evidence in support of their views. While they admit that...
Page 170 - Clark says that the eggs are arranged in it " in a single line, one after the other, at varying distances." It usually lies in the midst of the body, and extends from one-half to two-thirds of the length of the animal. "According to Balbiani's observations upon a closely allied species, when the eggs are laid they pass out from the ovary through an aperture near the mouth
Page 173 - ... similar apparatus at or near the mouth. Chilodon has a complete circle of straight rods around the mouth. As for the pivot it is nothing but a kind of stem, such as exists on a larger scale in Stentor, or is more particularly specialized in the pedestals of Epistylis, Zoothamnium, or Podophrya ; and as counter to what we see in these last, I would state that there are certain of the Vorticellians closely related to Epistylis, which have no stem whatever, and swim about as freely as Dysteria.
Page 95 - Burnet, and after him by Rudolph Wagner and Leuckart. They have always been spoken of as developing around decaying animal and vegetable matter. I was very much surprised to discover the manner in which they originate from such substances. I was studying the decomposing muscle of a Sagitta, a little crustacean, as I consider it...
Page 96 - ... of the fibre were agitated and waved to and fro as if to get loose, which they did from time to time, and, assuming a curved form, revolved each upon its axis and swam away with amazing velocity. There was no doubting, after this, the identity of the Vibrios and...
Page 17 - ... glass tube filled with asbestos and platinum sponge was used instead of the iron tube filled with wires. The time during which the infusions were boiled varied as will be seen by the records, from fifteen minutes to two hours, and the amount of infusion used was from one-twentieth to one-thirtieth of the whole capacity of the flask, the object being to have the materials exposed to as large a quantity of air as possible. In the account which follows, especial mention is made, in. most instances,...
References to this book
[The correspondence ] ; The correspondence of ..., Volume 14; Volume 1866 Charles Darwin Limited preview - 2004 |