26 THE PLANT WORLD. 



labels by all odds the most convenient, as they can be at- 

 tached or detached almost instantly, and the label may bear 

 a statement of the particular cross that is being made. In 

 order to secure a satisfactory quantity of seed it is nearly 

 always necessary to repeat the process of pollination several 

 times between the same two parents, and the inscriptions on 

 the tags prevent errors in the way of mixed parentages, even 

 when a large number of sister plants are being operated upon 

 simultaneously. 



For removal of the anthers I find most useful a pair of 

 forceps, different sizes and styles being best suited to different 

 cases. A needle-pointed forceps serves for both dissection 

 of the buds and removal of the anthers in the case of Bursa, 

 but in most flowers of larger size a broader pointed forceps 

 is preferable. I prefer to remove the anthers with as little 

 injury to adjacent parts as possible, but when the perianth 

 is thick and elastic so as not to allow easy access to the sta- 

 mens on merely opening the buds, as is the case in Verbas- 

 cum, it is desirable to remove it. For this purpose a small 

 curved dissecting scissors is very satisfactory. 



For the conveyance of the pollen to the chosen stigma 

 the method must again be varied to meet the requirements 

 of the material. In the majority of cases it is most satisfac- 

 tory to detach the flower which is to supply the pollen and 

 carry it in such a way that nothing comes in contact with the 

 anthers, which are then touched directly to the stigma. The 

 pollen plant is uncovered only long enough to allow the re- 

 moval of the flower to be used, and the pistil plant only long 

 enough to receive the pollen, the bag being replaced in both 

 cases as quickly and carefully as possible. In certain cases 

 this ideal technique is impossible. For example, in Helian- 

 thus annuus the method of handling individual flowers is 

 not feasible, and here it is my custom to use camel's-hair 

 brushes. One brush is used for each pair of heads to be 

 crossed. When not in use this brush is kept securely enclosed 

 in an ordinary seed-bag which bears the pedigree-number of 



