A course of practical instruction in elementary biology / by T. H. Huxley, assisted by H. N. Martin.

  • Martin H. Newell (Henry Newell), 1848-1896.
Date:
1875
Catalogue details

Licence: Public Domain Mark

Credit: A course of practical instruction in elementary biology / by T. H. Huxley, assisted by H. N. Martin. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    4. Movements: a. Watch the process of formation of a pseudopodium. A hyaline elevation at first; then, as it increases in size, currents carrying granules flow into it. b. Locomotion : watch the process,—a pseudopodium is thrown out, and then the rest of the body is gradually drawn up to it. c. If the opportunity presents itself watch the pro- cess of the ingestion of solid matters. d. [Observe the movements on the hot stage; warmth at first accelerates the movements, but as the tem- perature approaches 40° C. they cease, and the whole mass remains as a motionless sphere.] e. [Effects of electrical shocks on the movements.] 5. Mechanical Analysis: crush. The whole collapses, ex- cept sometimes the nucleus, and even that after a time disappears: there is no trace of a distinct resisting outer sac. 6. Chemical Analysis: Treat with magenta and iodine. The whole stains, and there is no unstained enveloping sac. Iodine as a rule produces no blue coloration; when blue specks become visible it is probable that the starch which they indicate has been swallowed. 7. [Look for encysted specimens : and for specimens which are undergoing fission.] 8. Another form of Amoeba is not unfrequently found which differs from that just described in being much less coarsely granular, and in having no well-defined ectosarc and endosarc, and also in having much longer, more slender and pointed pseudopodia.