18 Newcombe, Sensitive Life of Asparagus plvmosus. 
The tips of all 3 main axes and of some of the branches were 
dead. These shoots were now cut awa}^, and the pots set again 
in the dark to watch developments. After 4 weeks, 2 of the 
rhizomes each sent up a slender shoot which continued to grow 
in the dark for over three and one-half months when engagements 
obliged me to end the experiment. From material stored in the 
rhizoine and roots, therefore, two of these plants had continued 
growth for a year lacking 5 weeks. The 2 etiolated plants had 
borne altogether 7 branches. The total length of main axis and 
lateral branches was for one plant 266 cm, for the other 133.5 cm. 
This is a truly remarkable growth when one considers how small 
were the rhizomes and roots which furnished the material. 
Basides the great elongation of the main axis, a characteristic 
of the etiolated shoot is the absence of branches. The appendages 
of the normal vegetative shoot are the nodal scales, the needle- 
bearing branches, and the needles. Of these 3, the etiolated shoot 
bears usually only the nodal scales. These scales seem, on the 
etiolated axis, to present about the same appearance as on an axis 
growing in the light. The needle-bearing branches of the first 
Order would have numbered on the most of my experimental plants 
10 to 20, had the plants been grown in the light. On only a few 
of the scores of etiolated axes have any needle-bearing branches 
appeared. Those axes that have shown branches were generally 
dead at the tip. However, 3 etiolated main axes did produce 
1 to 4 lateral branches each, and with the main tip still living. 
Somewhat more numerous than the needle-bearing branches are 
the clusters of needles on the etiolated shoots. Since the main 
axis grown in the dark does not generally produce branches, one 
can look for the clusters of needles only at the nodes of the main 
axis. These needles are found on the etiolated shoot at not more 
than one node in twenty-five; most plants show none. When pre¬ 
sent on the etiolated shoot, their number in a cluster is greatly 
reduced, being from one to five, whereas on the shoot grown in 
the light, they would run from 7 to 25. The reduction in number 
probably is referable to the lack of elongation, as, with a lens, 
several very short needles can be seen in the clusters of the 
etiolated shoots. 
No matter how long a shoot is kept in the dark, it remains 
remarkably sensitive to light, considering the fact that etiolated 
stems generally are more slowly responsive to a heliotropic Stimulus 
than are those not etiolated. 1 ) A reference to a single representative 
experiment will suffice for illustration Five shoots that had been 
growing in the dark for 8 months were exposed in a window to 
light reflected from the sky. The temperature was 23°. In an 
hour all 5 shoots had made strong, positive, heliotropic curves of 
over 30°. 
J ) Pringsheim, Einfluß der Beleuchtung auf die heliotropische Stim¬ 
mung. (Beitr. Biol. Pflanzen. IX. 1907. p. 263.) 
