Doyle — Some Researches in Experimental Morphology . 409 



between stock and scion at the grafting-place would have been most awkward 

 to deal with had a younger and smaller leaf been chosen. This is especially 

 so in Pelargonium sonale, as a glance at any specimen will show. 



An incision was then made with a very sharp razor into the cut-end of 

 the petiole. This was made in different planes. In some cases it was 

 horizontal, in some cases vertical, in some cases oblique. A small apical bud 

 was then selected, one with the little interuodes as long as possible. A bud 

 two centimetres long, however, was looked on as quite a large bud. All the 

 leaves were removed from it, save about one. This is to leave the scion with 

 actively metabolic leaf-tissue. If one leaf was too small, a second with one- 

 half removed was also left. The cut-end of the bud was then carefully cut 

 to a tliin wedge shape, with the edge of the wedge as fine as possible. This 

 was inserted on the petiole of the stock, bound, as usual, with bast, and the 

 bud and the bast carefully sprinkled. The mother-stem above the petiole 

 selected was removed, as also were all the buds on the plant. Usually one or 

 two leaves were also left on the stock, so as to ensure a continuous supply 

 of food material to the mother-plant while the graft was taking. In Pelar- 

 gonium sonale, however, such was not essential. 



Obviously it is essential to keep down the transpiration of the scion till 

 the graft-union is effected. The most convenient way of keeping the grafts 

 in a very damp warm atmosphere is to cover them with a bell-jar, embedding 

 its rim in the sand-bed. 



All the plants had to be gone over every day to remove the adventitious 

 buds, which grew with great rapidity. Even after the graft had taken, 

 these adveutitous buds grew continually. 



The grafts took quickly^the bast binding could usually be removed 

 after ten days. 



Plate XXVIII, fig. 1, shows a graft of Pelargonium zonale a short while 

 after tlie graft was thoroughly established. The mother-stem in the bottom 

 right-hand corner, the petiole attached to the actively growing scion, and 

 the grafting zone are clearly distinguishable. The difference mentioned 

 above between the bud tliickness and the petiole thickness is also seen. 

 Attention is also directed to the very definite difference in size between 

 the petiole and the mother-stem. 



Plate XXVIII, fig. 2, is more interesting. It was photographed about a 

 fortnight after the graft had well taken, shows the wedge very clearly, and 

 gives a good idea of the size of bud used. But tlie label shows the method 

 of numbering. When many plants were in use, some system was necessary. 

 We see then on the label the name P. dioica. The capital A denotes that it 

 is a sprout grafted on a petiole. Plants dealt with in other ways were referred 



