292 



THE NURSERY-BOOK. 



it has been emasculated in this fashion. Fig. 97 represents two 



flowers of Nicotiana affinis, one of which has been cut. One 

 of the most important features of this method 

 is the marking of the fruits which results 

 in all species in which the calyx persists. 

 The calyx, of course, does not develop and 

 the crossed fruit can be distinguished at 

 once, even though the label is lost. The 



Fig. 96 Emascu- tomato fruit in Fig. 98 lacks entirely the long 



lated tomato- leaf -like calyx lobes at the base. Fig. 99 shows 



flower. upon the right a gooseberry fruit, of which the 



flower was cut, while that on the left illustrates an untreated 



fruit with the long persistent calyx. This marking of the calyx 



is useful in all the pomaceous fruits, 



like apples and pears, and even in 



capsular fruits, like phloxes and petu- 

 nias, in which the calyx lobes remain 



green. 



As soon as the flower is emasculated 



it must be securely tied up with a bag, 



to exclude pollen, as seen in Fig. 100. 



Netting of any kind is not safe in ordi- 

 nary practice, for the pollen grains are 



small enough to pass through it. It 



often happens that the flower-stem is 



not strong enough to hold the bag, nor 



large enough to allow the bag to be 



puckered tightly about it. In such 



cases, all the remaining flowers in the 



cluster should be removed and the bag 



should be tied over a portion of the 



branch. The branch will often need 



to be cut off to accommodate the bag. 



If there are many large leaves about 



the flowers, part of them will need to 



Fig. 97. Nicotiana affinis. 



be cut off. It is always a good practice to emasculate two or 

 three flowers in the cluster or all those of the same age in. 



