Newcombe, Sensitive Life of Asparagus phimosus. 41 



includiug needles take the same horizontal, diageotropic position; 

 3) twining shoots from the rhizomes which grow erect for 40 to 

 60 cm, and then begin to twine, rising from one to several meters, 

 finally bending the apical 10 to 15 cm over into the horizontal 

 Position, at the same time unfolding buds along the spiral stem 

 and along the terminal horizotal portion, the branches of all Orders 

 taking the horizontal, diageotropic position. 



2. The horizotal or oblique position taken by the various 

 parts of the aerial shoot is due to a reversal of response to gra- 

 vitation. the shoots being at first negatively geotropic. 



3. Seedling shoots are able when grown in complete darkness 

 to take the plagiogeotropic position as well as those grown in 

 light; but aerial shoots from rhizomes require the presence of light 

 to" enable them to attain and retain the horizontal position. 



4. Tho all kinds of shoots are positively heliotropic, the di- 

 rection of light has nothing to do with the development of dia- 

 geotropism, except that it may determine the plane of the dia- 

 geotropic curve, by first causing a heliotropic curve, and thus 

 giving gravitation a footing for the development of diageotropism. 

 there is no evidence of geonasty or photonasty. 



5. The influence of light on the development of diageotropism 

 can be marked for at least 8 days after the plant has been placed 

 in the dark. 



6. Growing shoots, revolved abont the horizontal axis of the 

 klinostat, develop to maturity with no indication of diageotropism. 

 The shoot develops its branching system with the same arrange- 

 ment of parts as in an ordinary orthotropic plant, quite unlike the 

 habit of this Asparagus. 



7. When the aerial shoot becomes diageotropic and horizontal, 

 it is still in morphology and physiology radial. 



8. The elongation of the aerial shoot is brot to an end by 

 the action of light. In the dark, growth seems capable of con- 

 tinuance as long as food lasts. 



9. Only in seedling shoots do the lateral buds unfold in the 

 dark. 



10. The spinous nodal scales of the main axis of the aerial 

 shoot are helpful in climbing, and develop about as well in darkness 

 as in light. 



11. The unfolding of lateral buds on the normal shoot seems 

 to be phasogenic, as they do not unfold tili the end of the growth 

 of the main axis is near. This relation may indicate why the buds 

 unfold on seedling shoots in the dark, growth being here brot to 

 an end by lack of food, but do not unfold on shoots from rhizomes, 

 these latter shoots w T hile in the dark being supplied for a year or 

 more with food from rhizome and roots. 



12. The reversal of response to gravitation is also phasogenic, 

 since it appears at the same time as the unfolding of lateral buds, 

 being therefore related to the cessation of growth of the main axis. 



13. The unfolding of lateral buds cannot be conditionned by 

 the inception of diageotropism; for the branches develop on the 



