8 ANNALES DE L'INSTITUT PASTEUR 



\Alicn Nve cul Irom a slem a pièce containing onc node, 



FiG. 1. FiG. 2. 



FiGS. 1 and 2. — Sister leaves dipping with their apices in water. Leaf in 

 fig. 2, wilhout stem, lias formed four shoots in four différent notches. Leaf 

 in fig. 1, attached to a pièce of stem, has just commenced to form one tiny 

 shoot in one nolch. The material wich caused shoot production in leaf 

 2 was utilized by the stem in leaf 1 for the production of a large shoot on 

 the stem, for callus formation at the basai end of the stem, and for a slight 

 geotropic curvature. The drawing was made seven weeks after the begin- 

 ning of the experiment. 



detach one of the two leaves, leaving the other leaf attached 

 to the pièce of stem (figs. 1-2), and allow both leaves to dip 



