454 



QUANTITATIVE LAWS IN REGENERATION. Ill 



///, Small and Large Pieces oj the Same Stem. 



A third series of experiments was as follows: Long pieces of stem, 

 containing about 10 nodes, were cut out from the same plant more 



^^. 



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Fig. 6. Five pieces cut from the stem of the same plant, (1) and (2) apical 

 pieces with 1 node each, (3) middle piece with 6 nodes, and (4) and (5) the basal 

 pieces with 1 node each. The large middle piece produces larger shoots than 

 either the more apical or more basal small pieces. The large middle piece has 

 ample roots while only the longer basal piece commences to form a root. Dura- 

 tion of experiment October 25 to November 21, 1921. 



than 1 year old (Fig. 6) . The middle piece of about 6 nodes (piece 3 

 in Fig. 6) served for the experiment, two small pieces, 1 and 2, con- 

 taining 1 node each and situated apically, and 2 small pieces, 4 and 5, 

 also containing 1 node each, situated basally from the large middle 



