Randolph : Influence of moisture upon ivy 



95 



the presence or absence of absorptive roots from the stem. The 

 secondary roots increase in length and are not distinguishable in 

 appearance from the ordinary roots that arise from the stem. 



Figure 2. Traced from a photograph of young stems growing in water in air sat- 

 urated with moisture, cut in May when the holdfast-roots had begun to appear. Many 

 of the holdfast-roots (kr) have continued to grow, but the part grown in saturated air 

 (Ara) has a different structure from that of the original holdfast-roots. The holdfast- 

 roots' nearest the growing end of the stem had scarcely appeared when the stems 



were cut. 



If the slips in water are kept in an atmosphere saturated with 



moisture 



in the air, above the surface of the water in which the stems are 

 standing. They appear to arise indifferently on stems with leaves 

 ,nH ™ c **m C frr.m writ'rh the leaves had been cut off at the begin- 



