30 LABORATORY MANUAL OF GENERAL PHYSIOLOGY 



Observe streaming of granules. The movements soon subside. Repeat 

 several times (cf. Herrera, in Alexander's "Colloid Chemistry," vol. 2, 

 p. 85, 1928). 



12. Cyclosis and Battle of the Protozoa. — (a) Place a drop of 14% 

 NaOH containing India Ink into a watch glass containing equal parts 

 gasoline and olive oil. Observe the protoplasmic streaming under the 

 microscope, (b) With a rotary motion stir the NaOH rapidly with a 

 needle, keeping the point touching the glass. Quickly observe under the 

 microscope. Focus on the path made by the needle. Observe the amoe- 

 bae fiercely gnawing each other in the line of battle. 



13. Robertson's Camphor Amoeba. — Drop a mixture of 10% camphor in 

 benzol on water on white background. Note movements. Explain (cf. 

 Robertson, Science, vol. 36, p. 446, 1912). The fluttering of the margin 

 resembles the macrophages in Lewis' films of tissue cultures (but with a 

 different time scale). Text p. 173- 



14. Sjmthetic Fungus. — Allow a drop of sodium silicate solution to 

 fall from a height of 2 cm. into a film of concentrated HCl in a watch glass. 

 Add a few cc. of distilled water. Note the form resembling a culture of 

 bacteria or mold. Carefully observe under microscope. In a ring near 

 the center will be found formations of spores. Formation of crystals 

 may partially obscure result. The preparation is permanent and can be 

 mounted on a slide in balsam. The HCl infiltrates through pores in the 

 silica membrane (cf. Alexander's "Colloid Chemistry," vol. 2, p. 87; 

 also Herrera, Memoria de la Sociedad Cientifica "Antonio Alzate," 

 Mexico, 26: 44, 1907). Text pp. 164, 166. 



15. Osmotic Growth. — Suspend by a thread a crystal of ferrocyanide 

 in a test tube containing 3% CUSO4 solution. Observe growth. 



16. Galvanotropism of Artificial Plants. — Fill an upright specimen 

 jar with 3% CUSO4. At each end place electrodes of sheet copper con- 

 nected to four dry cells in series (with key in circuit). Drop a few crystals 

 of ferrocyanide into the jar. Place a light behind the jar. When upward 

 growth begins turn on current. Toward which pole do the plants grow? 

 (cf. Beutner, "Physical Chemistry of Living Tissues/' Fig. 8, 1933)- 



17. Colony of Calcareous Sponges. — Place several small pieces of 

 anhydrous CaCU close together in a Petri dish containing Le Due's 

 solution (potassium carbonate 76 parts, sodium sulphate 20, tribasic 

 potassium phosphate 4, all saturated). Quickly observe under microscope. 

 Focus on outer edges of the clump of CaClo. Observe slow streaming 

 into osmotic growths which becomes almost imperceptible after three 

 minutes. After 10 mins. radial spicules appear. For typical sponges see 

 Cambridge Natural History, vol. 1, Figs. 79 and 88. According to Ger- 

 arde's "Herbal" 1636, sponges are formed "of the foame or froth of the 

 sea." 



