28 LABORATORY MANUAL OF GENERAL PHYSIOLOGY 



duce both separately. Observe that fine glass particles gather at the sur- 

 face of the drop (cf. Rhumbler, Arch. Entwicklungsmech., 7: 283, 1898). 



5. Cell Division (Animal). — Mix olive oil with chloroform until the 

 mixture is heavier than water. Place a drop in distilled water. Allow 

 N/3 NaOH to flow from two glass tubes one at either side of the drop or 

 apply a small crystal of NaOH at each end. Explain the cleavage (cf. 

 Gellhom, "Lehrbuch allgemeine Physiol.," pp. 495-6, 1931; Gray, Quart. 

 Jl. Micr. Sc, 66: 235, 1922). Text p. 171. 



6. Cell Division (Plant). — Wet a fine thread with N/5 NaOH. Lay 

 thread over middle of drop of oil-CHCU mixture in distilled water. 

 Try a coarse thread. Explain result. The thread represents the cellulose 

 wall. A partition of minimal area, when two dimensions of a cell are 

 small compared with a third as in a filament like Spirogyra must be 

 transversely to the long axis (cf. D'Arcy Thompson, "Growth and 

 Form," p. 358, 1917). 



7. Biological Diffusion Patterns. — Pour a film of half saturated KNO3 

 into a Petri dish resting on a white background. Allow a few drops of 

 % saturated KNO3 containing eosin and India Ink (recently added) to 

 fall on the film from heights of to 4 ins. Observe the patterns which 

 slowly unfold — ferns, neural folds, finger prints, etc. Leave undisturbed 

 and proceed with the next experiments. 



8. Mitosis. — Place a drop of half saturated KNO3 on a glass plate 

 resting on a white background. This represents the cytoplasm of the cell. 

 In this carefully place a drop of the same solution deeply colored with 

 India Ink (nucleus). On opposite sides of the drop place two drops of 

 ^^ saturated KNO3 stained with eosin. With a needle bring the drops in 

 contact. Chromosome movements, asters, mitotic spindle, and align- 

 ment of chromatin on an equitorial plate may appear. Repeat 3 or 4 

 times (cf. LeDuc, "Mechanism of Life," Fig. 32). 



9. Biological Theory of Brownian Movement. — Into a watch glass 

 containing a mixture of equal parts of gasoline and olive oil drop 14% 

 NaOH from a height of 60 cm. Quickly observe under microscope. Focus 

 on small drops near surface. Explain movements (cf. Herrera, in 

 Alexander's "Colloid Chemistry," vol. 2, p. 91, 1928). Note semblance to 

 movements of bacteria. 



10. Synthetic Colpoda. — Place a few drops of Herrera' s solution B 

 (water 100 parts, soda 14, rodamine 1) into a watch glass containing 

 Herrera's Solution A (gasoline 100 parts, olive oil 50) and quickly observe 

 under microscope stained forms. Observe cyclosis (cf. Beltram, Trans. 

 Amer. Micros. Soc, 46: 69, 1927). Text p. 173- 



11. Resin Model of Protoplasmic Streaming. — Add a drop of 14% 

 NaOH to a mixture of gasoline 100 parts, olive oil 50 and resin 25 parts. 

 Quickly observe under microscope. Focus on large yellow masses. 



