2406 



Journal of Applied Microscopy 



a klinostat. After the first few revolutions the water in the dish has practically 

 the same rate of motion as the dish itself. The speed of the klinostat should be 

 so adjusted that the water in the margin of the dish will have a velocity of^50 to 

 100 cm. per minute. Suspend seedlings of Fagopynim esculentum, Raphauus 

 sativus, or Zea Mais (popcorn) from the wooden bar in the clamp. Make obser- 

 vations at the end of fifteen to twenty-four hours. 



TRAUMATROPISM. 



The curves produced by wounds of various kinds are among the most pro- 

 nounced and characteristic we know. (Fig. 21.) Select seedlings of Lupitius 

 albus, Pisiim sativum, or Vicia Faba when o to cm. long and attach them to a 



Fig. 21. — Pisum sativum seedlings ten hours after wounding with a hot rod. 



suitable support in a damp chamber. Attach a bit of thin copper 2 mm. square 

 to the sloping side of each root-tip. Fasten similar bits of copper or paper to 

 other roots 3 or 4 mm. back from the tip. The thin pieces of copper may be 

 obtained by hammering out the end of a copper wire. Other roots may be 

 touched in corresponding places with a hot glass rod or a bit of solid potassium 

 hydroxid. Care must always be taken against making a wound so severe that it 

 kills the meristematic tissue. 



Make observations ten to twenty-four hours after applying the stimulus and 

 attempt to correlate the results. Howard S. Reed. 



University of Missouri. 



