V38 SENSITIVENESS OF THE APEX Chap. Ill 



9 h. very slightly curved from the card ; after 24 h. tip curved 

 towards card. Eefixed new square laterally, attar 9 h. distinctly 

 curved from the card, and after 24 h. curved at right angles frcm 

 the perpendicular and from the card. 



(24.) A rather large oblong piece of card fixed with shellac to 

 apox : after 24 h. no effect, but the card was found not tp be 

 touching the apex. A small square was now refixed with 

 shellac ; after 16 h. slight deflection from the perpendicular 

 and from the card. After an additional day the radicle became 

 almost straight. 



( 25.) Square of card fixed laterally to apex of young radicle ; 

 after 9h. deflection from the perpendicular considerable; after 

 24 h. deflection reduced. Eefixed a fresh square with sheUac: 

 after 24 h. deflection about 40° from the perpendicular and from 

 the card. 



(26.) A very small square of card fixed with shellac to apex of 

 young radicle : after 9 h. the deflection from the perpendicular 

 and from the card amounted to nearly a right angle; after 24 h. 

 deflection much reduced ; after an additional 24 h. radicle almost 

 straight. 



(27.) Square of card fixed with shellac to apex of young 

 radicle : after 9 h. deflection from the card and from the perjien- 

 dicular a right angle ; next morning quite straight. Refixed 

 a square laterally with shellac; after 9 h. a little deflection, 

 which after 24 h. increased to nearly 20° from the perpendicular 

 and from the card. 



(23.) Square of card fixed with shellac; after 9 h. some 

 deflection ; next morning the card dropped off; refixed it with 

 shellac; it again became loose and was refixed; and now on tlie 

 third trial the radicle was deflected after 14 h. at right angles 

 from the card. 



(29.) A small square of card was first fixed with thick gum- 

 water to the apex. It produced a slight eS'ect but soon fell 

 off. A similar square was now affixed laterally with shellac : 

 after 9 h. the radicle was deflected nearly 45° from the perpen- 

 dicular and from the card. Alter 36 additional hours angle of 

 deflection reduced to about 30°. 



(30.) A very small piece, less than J^th of an inch square, of 

 thin tin-foil fixed with shellac to the apex of a young radicle ; 

 after 24 h. no effect. Tin- foil removed, and a small square of 

 sanded card fixed with shellac ; after 9 h. deflection at near!) 

 right angles from the perpendicular and from the card. Next 



