EXPERIMENT WITH A PLANT 149 



yet burst in it (i.e. a little younger than the one 

 shown in Fig. 31), that is to say, of such an age that 

 the ovules in it have not yet been fertilised. The 

 reader is recommended to discover the external ap- 

 pearance of the latest stage in the growth of the flower 

 at which the anthers usually burst, by picking, say, 

 ten stages in the development of the flower, ranging 

 from a bud in which the petals do not extend beyond 

 the sepals, to the nearly open flower. The stage, 

 in the development of the flower, at which the 

 pollen is set free will be found to be much earlier 

 than was expected. A flower, at a stage of develop- 

 ment preceding this, must be selected to function as 

 what we may, for convenience sake, call the female 

 parent, or female flower. 



Having described the appearance of the flower 

 suitable to function as female parent, we can proceed 

 to a description of the method by means of which one 

 variety may be crossed with another. A very simple 

 set of implements is required for this — (1) a pair 

 of fine forceps ; (2) a pair of fine scissors ; (3) a 

 glass tube, or wide-mouthed bottle with cork 

 stopper, to contain methylated spirit. A hand 

 lens is also a desirable addition but is not a 

 necessity. 



Having selected the flower of the right age to 

 function as female plant, the first thing is to make 

 certain that it has not already fertilised itself, by 

 seeing that the anthers have not yet burst (with a 

 hand lens if available) ; the next thing to do is to make 

 it impossible for the flower to be self-fertilised, and 



