260 
BOTANICAL GAZETTE 
[OCTOBER 
The actual area of the cell walls of the hard bast elements and 
their number was found by method 4, and the total xylem area by 
method 3. 
TABLE I.—Helianthus annuus 
ae A 
NOVEMBER NovEMBER DECEMBER DECEMBER A |82h [ea] so 
21 28 14 20 im at aes Bet. ee 
No. or —| 25 |g82 188) =x 
PLANT G22 seb Zi we z¢ 
Height| Diam.) Height | Diam.| Height | Diam.|Height| Diam.| 224 |3583/ 0%) #2 
in in in in in in in in | BES |qons] oa] Fe 
cm. mm. | cm. mm. | 4 ‘) ZA | we 
Exp. 8 
ee 19. | 4. | 29. | 4. | 50.4] 4. | 59.2] 4.2 | 7711] 6.837) O91 ce 
Gr 15600) 9.24 3g. ER dae Be 4.1 | 41.6] 4.2 | 5443] 7-014} 811) ©. 
eG ks 10.6 | 3-5 | 19. | 3.5 | 37-8 | 3.6 | 44.7] 3.5 | 5216] 6.430] 840 25 
4...+.|/11.8 | 3.1 | 20.7 | 3.2 | 35.3 | 3.6 | 44.1] 3.9 | 4626] 5.488) 682) 5. 
ere Q. 2. 20.2 | 2, S625 53. 44.1| 3.2 5443) 5-666 ds Baeall 
Total |63.5 [15.8 |107.9 (15.9 |194.0 |18.3 |233.7|/19.0 287.49|31 -435|3005|33-5_ 
Av....|12.7 | 3.16) 21.58] 3.18] 38.8 | 3.66/46.74 3-8 |5749.8| 6.287) 721 ot 
Control 6.6 
ere 15-2 | 3. | 22.7 | 3. | 42.8 | 4.1 | 52.9] 4.3} 5352] 5-145 39 3 
Pe: Joe ee ee yee oa eee oe a eee 3039| 6.420 ; a 
Toss 11.3] 2.5 | ¥9. -| 3: | 34. | 3.4.| 41.6] 3.5. | 3729] 5-374] O57 7 
Bee, Ir.3 | 3-2 | 18.3 | 3.2 | 34. | 3.2 | 39. | 3-5 | 2494] 5-498 or e 
Sao Q- | 2.2 | 12.1 | 2.2 | 23.3 | 3.2 | 30. | 3.4 | 3629] 4-679] 950) 3 
Total |58.6 |14.4 | 89.7 [14.9 |168.1 17.7 |206.3/18.5 | 18233 27 .114)324823-8 
———- ; 6 
Av 11.72) 2.88) 17.94) 2.98] 33.62] 3.54|41.26| 3.7 3647] 5.423] O48] 47 
The percentages of increase in the experimental plants over the 
controls are the following: breaking strength 57.6 per cent.; cross 
section of walls of hard bast 16 per cent.; number of hard bast ele- 
ments 12.5 per cent.; and xylem area 4o per cent. 
TABLE Il.—Helianthus annuus 
paver an ay 
i Dis- reak 
Height] Di ee 
No. of eats ad_| above rst pait | Oren yistrength 
plant Height in cm. pair of ror nee below ad in kg 
a ae ree 
aU uly 
June | June | June | June June | June | July | July | June | July od . 
Exp. 21 -| 22 4 26 28 30 I I 21 < ax [16.535 
Av..... 7-5 | 8.6 |12.6 |16.3 19.4 {23.8 |26.6 |10.4 | 4-1 7-26) 3- 5 
Con 13-799 
AX ae 7-03) 8.2 |11.3 |14.3 17.3 at.5 |24.3 | 9.2 | 4.1 | 7-43 3-7? pees 
