4 AN.\ALES J)E I/I.XSTITUT PASTEUH 



Kach noile of Ih-ijophijUum gives rise lo two leaves of equal 

 size. The writei- l'oiind ihat when two such sisler leaves are 

 isolaletl and kepl under idenlical conditions Ihey produce in 

 equal timc equal masses of shoots, as Table I indicates. Nine 

 pairs of sister leaves were isolated and kept for 31 days on 

 moist lilter paper. The one set of nine leaves, weighing 

 12,022 gm., produced in that time 1,436 gm. of shoots; the 

 nine sister leaves, weighing 11,861 gm., yielding 1,348 gm. ot 

 shoots. 



Table I. 



Equal masses of sister leaves produce, therefore, approxi- 

 mately equal masses of shoots in the same time and under 

 equal conditions. In this case the number of shoots in the two 

 sets of sister leaves was not very différent; we can easily cause 

 a grealer différence in the number by leaving one set of leaves 

 intact and cutting their sister leaves into four pièces. Table II 

 gives the record of such an experiment in which eight pairs of 

 leaves were used ; eight leaves were left intact while each of 

 their sister leaves was eut into four pièces. Duration of 

 experiment 3S days. 



Table II. 



