102 Ewart and Rees.—■Transpiration and the Ascent of 
the whole wood cylinder. The influence of the eddy currents and lateral 
exudation will increase as the pressure and resultant velocity of flow 
increase. 
Experiments on Rate of Ascent of Sap in Dead and Living 
Cut Branches in Dry and Saturated Air. 
Method. Living and dead stems devoid of leaves were saturated with 
water and placed with their basal cut ends in a vessel of eosin in 
a saturated atmosphere or exposed to air. The stems were all saturated 
by driving water in under pressure, since it was found impossible to 
saturate them fully by drawing in water by means of a suction pump. In 
injecting the stems no blocking occurred if a fresh surface was cut under 
water before attaching to the pump and distilled or filtered water was 
used. After a certain length of time the height to which the eosin had 
ascended in the different stems was noted. 
I. Acacia mollissima. 
(a) Living stems saturated with water by means of high-pressure 
pump. 
Temperature 22°. 
(i) In dry air . 
Duration of exp. Rate of ascent per hour. 
1. 2 hours 14.1 cm. 
2. 2 hours 11-25 cm - 
(ii) In saturated atmosphere. 
1. 2 hours 4-65 cm. 
2. 2 hours. 8-5 cm. 
( b ) Stems killed by injecting mercuric chloride and then saturated 
with water by means of high-pressure pump. 
(i) In dry air. 
1. 2 hours 5 cm. 
2. 2 hours 5 cm. 
(ii) In saturated atmosphere. 
1. 2 hours 1.5 cm. 
2. 2 hours 3*5 cm. 
II. Encalyptus amygdalina. 
(a) Living stems saturated with water by means of high-pressure 
pump. 
Temperature 21° 
(i) In dry air. 
Duration of exp. Rate of ascent per hour. 
1. I hour 27 cm. 
2. 1 hour 15 cm. 
(ii) In saturated atmosphere . 
1. 1 hour 
2. 1 hour 
12 cm. 
15 cm. 
