112 



Jean White : 



Taxus baccata. 

 Thickness of Walls Internal Diameter 



Red Wood White Wood Ked Wood White Wood 



.004 mm. .008 mm. .010 mm. .008 mm. 



.006 ,, .006 ,, .009 ,, .008 ,, 



.006 ,. .007 ., .008 ,, .008 .. 



The above results appeared to indicate that the thickness of 

 the tracheide walls might be influenced by either pre.ssure or illu- 

 mination, or both. 



In order to investigate this matter further, some of the lateral 

 branches of Cedrus deodara.. Thuja orientalis, Callitri.s (lunnii, 

 Cryptomeria elegans, and Pinus strobus, were curved rnund and 

 tied in the >ame manner as were those described by Professor 

 Ewart and Mr. Mason-Jones. ^ The plants were set upright in 

 the glass-house on 21st May, 1907. Parts of the lateral branches 

 of Taxus baccata, Podocarpus elata, a-iid Araucai-ia excelsa were 

 bound round with tinfoil, and the pot« were laid hcrizontally in 

 the glass-house, and the uppermost part of the pot marked, also 

 on 21st May, 1907. 



1 Annals of Botany, vol. xx., |). 202. 



