CH. Vl] FLORAL APEX, ETC. 49 



several events, among which the following are the more 

 important. 



The principal dome of the flower almost always ceases 

 to grow at a relatively early date, and we therefore find 

 it eventually either sunk down among, or below the bases 

 of its lateral outgrowths ; or we find that it has undergone 

 even more profound alterations e.g. the apex may be 

 bodily converted into some special organ. 



The lateral outgrowths themselves are so crowded 

 together on the restricted area of the non-enlarging dome, 

 that their positions are perforce altered as compared with 

 those of ordinary leaves, &c., of the shoot ; and, as a rule, 

 no internodes are developed. 



The young outgrowths are frequently forced into 

 such close lateral contact from the beginning, that their 

 growing bases become fused or concrescent : in other 

 words, they grow together and come off as a whole, rising 

 up from the floral axis as a common rim or ring of tissue 

 which carries up the hump-like incepts of the lateral 

 organs at first originated separately. This makes the 

 lateral organs look as if they had fused or stuck together 

 in their development. 



Another consequence of the crowded position of the 

 young organs is that some of them may be starved or 

 crowded out during development, owing to their not being 

 able to hold their own in the struggle for existence 

 with the others, and thus reductions in their numbers are 

 brought about as the flower matures. These reductions 

 or abortions of parts are ruled by the laws of natural 

 selection, and the causes which induce them are complex ; 

 but the process utilised is that mentioned, viz.: the parts 

 begin to develope, but do riot reach maturity, the flower 

 having become adapted to do without these particular 

 organs. 



w. in. 4 



