CH. VI, 12] MONSTROSITIES OF FLOWERS 341 



frequent abnormality consisting in a continued growth right 

 up through the center of the flower, above which it produces 

 a second flower, or else a leafy branch, as already described 

 in connection with stems (page 201). Sometimes two or 

 more of these abnormalities are combined in a single flower, 

 in which case we have a genuine, and often an extreme, 

 monstrosity (Fig. 150). One or more of the whorls may be 

 absent though normally present, or present when normally 

 wanting; and any or all may become altered in color, 

 multiplied in number, or converted entirely into a bunch of 

 green leaves. Regular flowers become diversely irregular, 

 and irregular kinds perfectly regular. Also flowers, especially 

 their pistils, become malformed to galls under insect stimula- 

 tion (page 203). It is surprising how many and diverse are 

 the abnormalities which appear when one's attention is 

 directed to these matters, and how many are described 

 and pictured in the special works devoted to the subject. Of 

 the latter the most famous and instructive is the classic 

 " Vegetable Teratology " by Masters, which the student will 

 do well to examine. 



Not only structural, but physiological abnormalities occur, 

 as for example in cases where the " resting-period " (page 378) 

 is wanting, and the flower opens in autumn instead of the 

 next spring, as happens with exceptional Strawberry blossoms 

 and flowers of shrubs. Of course such flowers are destroyed 

 by frost without chance to form seed. Sometimes the ab- 

 normality, especially in extreme monstrosities, occurs only 

 in a single flower, in which case it is usually not hereditary 

 and cannot be propagated, just as with fluctuating varia- 

 tions (page 314). But sometimes all of the flowers on one 

 branch or one plant exhibit the feature, in which case it 

 can usually be propagated like a sport, which indeed it 

 really is, both bud sports and seed sports of this kind 

 occurring. Hence we have in our collections the permanent 

 strain of the "Hose in hose" Primrose; in our greenhouses 

 we have a green Rose propagated as a curiosity; and in 



