Ch. IV, 12] MONSTROSITIES OF STEMS 



197 



produced, though others are true monstrosities resulting 

 from partial fission of one. Oranges sometimes exhibit a 

 segment very different in color and texture of skin from 

 the rest ; but these are a special incident of grafting, as else- 

 where explained (page 211). Strawberries which remain 

 hard, shrunken, and green on one side are merely individuals 

 which did not receive enough fertiliz- 

 ing pollen (page 279). And other 

 peculiarities of like sort, more or less 

 obvious in origin, occur in various 

 plant parts. 



Of true stem monstrosities perhaps 

 the most common are fasciations. 

 These are cases in which the usually 

 cylindrical stem with its single ter- 

 minal bud becomes a flattened stem 

 with several imperfectly separated 

 terminal buds, as occurs at times in 

 Asparagus (Fig. 143), Hyacinths, and 

 other herbs, and in Forsythia and 

 Barberry among shrubs. A striking 

 example, seemingly in a fruit, but 

 really in a stem, occurs in the Pine- 



17 7 Fig 143 Fasciated 



apple figured herewith (Fig. 144). sho ot of Asparagus, which 



Fasciations are much more Common is , normally cylindrical; 

 ,,. ,., .,, , j X 2- (Drawn from a pho- 



in cultivated than in wild plants, and tograph.) 

 sometimes can be propagated ; as, for 



instance in the Crested (i.e. a fasciated) Cactus (Fig. 145), 

 while a crested form of Celosia gives us the Cockscomb of 

 our gardens, and a related condition in leaves produces the 

 feathered fronds of the Pearson Fern, — a new variety of the 

 plain Boston Fern. Fasciations are evidently caused by a 

 partial fission of one meristematic growth center into several. 

 In some cases the result follows an injury by insects, but in 

 such cases it cannot be propagated ; in others it seems clearly 

 due to internal causes of still unknown nature, affecting the 



I 



