116 Otis F. Curtis 



supply of organic matter to be transported to and used by the roots. 

 The effect on roots, therefore, would be chiefly secondary. This point is 

 being tested experimentally. 



PART II. ORGANIC NUTRITION OF CUTTINGS 

 REVIEW OF LITERATURE 



Faivre (1871) clearly demonstrated that root formation in woody 

 cuttings is dependent on the food stored in the twig. He found also that 

 this food, as starch, disappears from the cutting when growth starts, 

 apparently being used in callus and root formation, or, if the tops appear 

 first, in their production. He demonstrated that this food passes down- 

 ward to the roots thru the phloem region. The fact that elaborated food 

 passes downward to the roots thru the phloem tissues was recognized 

 by Knight (1801) early in the nineteenth century. The paper he pub- 

 lished at that time states that when a tree is ringed the callus develops 

 only on the upper side of the cut, and that growth of the stem also occurs 

 only above the cut. He explains this on the ground that the food sub- 

 stances used in tissue building come from above. Later (1809) he stated 

 that substances used in forming roots must come down thru the bark 

 region, as, roots formed on a ringed twig will develop only above the cut. 

 It was clearly recognized by Sorauer (1895) that the roots of woody cut- 

 tings are dependent on a supply of food stored in the twig, and those of 

 herbaceous forms on food supplied by attached leaves. Ktister (1903) 

 states that callus formation is dependent on the amount of food available. 



Boehm (1883), Meyer (1886), Acton (1890), and others, have shown 

 that severed shoots or leaves, if placed in various sugars and other organic 

 compounds, will absorb some of these and store them as starch in the 

 leaves or the stems. It occurred to the writer, therefore, that possibly 

 immature twigs could thus be caused to take up and store a reserve supply 

 of food. If the food were thus stored, it might be possible to decrease the 

 leaf surface and the light intensity, thus decreasing the attendant labor of 

 regulating humidity and light while retaining the advantages to be gained 

 by using herbaceous or immature twigs. The treatment might also increase 

 the vigor of cuttings that root rather readily, and lengthen the season 

 during which woody cuttings can be taken. It was found that Ligustrum 

 cuttings taken before the middle of October were immature and produced 

 weak plants, while those taken the last of November had passed the rest 



