211 
Strychnos laurina. Wall. 
After 3 After 4 After 4 
AV Sst. weeks, At first. weeks, At first. weeks, 
Basal. Apical. | Basal. Apical. | Basal. Apical. | Basal. Apical. | Basal. Apical. | Basal. Apical, 
Boo atin 2 coils. 2 coils. 21/, coils. 
Concave. 24 . 36 26 . 36 18 . 30 95 . 35 24. 36 25 . 35 
Convex. 25 . 42 26 . 49 18 . 34 23 . 48 24. 40 24. 51 
1'/, coils. 21/, coils. | 3/, coil. | 1/5 coils. 
Concave. 25 . 34 Q7 . 34 23 . 35 95 . 38 0. 36 : 
Convex. 26 . 40 26 . 52 23 . 40 98 . 50 81 . 43 32 . 62 
11/, coils. 2'/, coils. | 3/, coil 2 coils. 
Concave. 25 . 36 27 . 37 33 . 37 95 . 35 25 . 36 29 . 43 
Convex. 26 . 42 26 . 48 25 . 44 96 . 52 27 . 43 28 . 66 
If the hook-tendril is young, both the concave surface , slightly, 
and the convex, markedly, increase in length. If adult, the 
concave surface, either undergoes no perceptible increase in 
length, or may even become slightly shorter, owing to the ex- 
cessive growth, and elongation, of the convex surface compressing 
the tissue on the concave side. As might be expected, the 
greater the thickness of the coiled portion, the greater is the 
difference in length between the concave and convex surfaces. 
The growth in length of the basal portion is nearly bilaterally 
symmetrical, but the original convex surface may become con- 
cave, causing a slight curvature in the opposite direction to 
that of the apical portion. 
The hook-tendril is physiologically bilateral, the concave sur- 
face being very much more irritable, than the convex, and the 
irritability is localized in the coiling apical portion, the most 
irritable region commencing about a centimetre trom the apex 
and extending backwards for 1 to 2cm. Thus a loose loop of 
twine, weighing 0.3 grm., touching the concave surface only, and 
at its most irritable part, caused, in 2 weeks, the hook-tendril to 
make 11/, coils, and to increase from 103. 104, at its originally 
