254 



Double CrosS'Gfratn 



longitudinal series. The consequence is that the rate of change in the 



inclination of the grain will not be uniform at any moment, resulting in 



the grain being composed of a series of superimposed serpentine curves. 



Although the general course of the grain in Chloroxylon Sroietenia 



1 1 H[ I lllhl I |iiJLj. l I I l|i 



jjijii |ini| 1 1 nmj ii«iiiii 1 1 1 i i 1 1 | in i| nm 



25 30 40 45 50 60 70 80 



rrrrt i miinIiiii li n ili m IiiiiIiiiiIiI i inliiiiliiiilii 1 1 I it 



LlJlLLL 



Fig. 6. Chloroxylon Swietenia. Transverse series. Scale as in Fig. 3. 



&n& Shorea robusta agree very closely together, yet, as might be expected, 

 there are numerous minor differences between the two species. 



The length of the period which in Shorea robusta ranges between 

 3 and 4 cms. has an average value of a little less than 1 cm. in Chloroxylon 



