IJnAP. la. OF THE RADICLE OF QUERCUS. 



175 



Fig. 68. 



remarkable cases are worth describing. The radicles 

 were examined on each successive morning, at nearly 

 the same hour, that is, after intervals of 24 h. 



No. 1. This radicle suffered from a series of accidents, dnd 

 acted in an anomalous manner, for the apex appeared at first 

 insensible and afterwards sensitive to contact. The iirst square 

 was attached on Oct. 19th ; on the 21st the 

 radicle was not at all curved, and the square 

 was accidentally knocked off; it was refixed 

 on the 22nd. and the radicle became slipihtly 

 carved from the square, but tne curvature 

 disappeared on the 23rd, when the square 

 was removed and refixed. No curvature en- 

 sued, and the square was again accidentally 

 knocked off, and refixed. On the morning of 

 the 27th it was washed off by having reached 

 the water in the bottom of the jar. The 

 square was refixed, and on the 29th, that 

 is, ten days alter the first square had been 

 attached, and two days after the attachment 

 of the Inst square, the radicle had grown to 

 the great length of 3'2 inches, and now o.,„ . i >• i 



the terminal growing part had become bent with square of card 

 away from the square into a hook (see 

 Fig. 68). 



No. 2. Square attached on the 19th ; on 

 the 20th radicle slightly deflected from it 

 and from the perpendicular; on the 21st 

 deflected at nearly right angles ; it remained during the next 

 two days in this position, but on the 25th the upward curva- 

 ture was lessened through the action of geotropism, and still 

 more so on the 26th. 



No. 3. Square attached on the 19th; on the 21st a trace of 

 curvature from the square, which amounted on the 22nd to 

 about 40°, and on the 23rd to 53° from the perpendicular. 



No. 4. Square attached on the 21st; on the 22nd trace of 

 curvature from the square ; on the 23rd completely hooked 

 with the point turned up to the zenith.. Three days afterwards 

 (i.e. 26th) the curvature had wholly disappeared and the apex 

 poinied perpendicularly downwards. 



No. 5. Square attached on the 21st ; on the 22nd dociclel 



attached to one side 

 of apex, causing it 

 to become hooked. 

 Drawing one-half 

 natural scale. 



