2318 



Journal of Applied Microscopy 



Make a 7 per cent, solution of gelatine, dissolving the gelatine on a water- 

 bath ; when the solution cools to 20° to 30°C. insert several straight seedlings, 

 allow the jar to stand until the gelatine hardens and invert it. Insert other 



Fig. 14. — Roots Inverted in Different Media. No. 1 in moist air ; No. 2 in water ; 



No. 3 in moist sawdust. 



seedlings in the cork of a wide mouthed bottle or pint jar at least 10 cm. in 

 diameter. When the jar is inverted there should be an air space of 2 to 3 cm. 

 above the surface of the water in order that a sufficient supply of oxygen may be 



Fig. 1.5. — A Culture Chamber with Sloping Glass Side. 



present. Other seedlings may be inverted in the damp chamber for 36 to 48 

 hours. 



10. Diageotropism of Roots. The diageotropic, or plagiotropic, growth of 



