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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    crushed transparent sacs; the soft crushed stained protoplasm. 5. Repeat observation 3, running in iodine solution instead of magenta. The protoplasm stains brown ; the rest of the cell remains unstained. Note the absence of any blue coloration ; starch is therefore not present. b. Treat another specimen with potash solution, running it in as before: this reagent dissolves out the proto- plasm, leaving the sac unaltered. 7. [Sow a few yeast-cells in Pastsur’s solution in a moist chamber and keep them under observation from day to day; watch their growth and multiplication.] 8. [Endogenous division: take some yeast which has been grown in Pasteur’s solution at a temperature below 20° C.; spread it out in a thin layer on fresh cut potato slices or on some plaster of Paris, and place with wet blotting paper under a bell-jar: examine from day to day with a very high power (800 diam.) for ascospores, which will probably be found on the fifth or sixth day.] B. Physiology. (Conditions and results of the vital activity of Torula.) 1. Sow a fair-sized drop of yeast in— a. Distilled water. 5. 10 per cent, solution of sugar in water. c. Pasteur’s fluid without the sugar. d. Pasteur’s fluid with sugar. [e. Mayer’s pepsin solution1.] 1 Mayer’s solution (with pepsin) = 15 per cent, solution of sugar-candy 20 cc. Dihydropotassic phosphate ou grm. Calcic phosphate ou grm. Magnesic sulphate ougrm. Pepsin 0-23 grm.