198 THE PATH OF DEGENERATIVE EVOLUTION 



ancestral stages, and thus there is no evidence that 

 degeneration retraces the path of progressive evolu- 

 tion. 



In the cauliflower (Brassica oleracea, var. Botry- 



tis), a cultivated 



i A s ,-^_. variety, the 



inflorescence 

 branches ex- 

 uberantly; most 

 of the flowers 

 produced on 

 these branches 

 are arrested in 

 their develop- 

 ment. Of the 

 immense num- 

 ber of flowers 

 produced on 

 each plant only 

 a few attain 

 sexual maturity 

 and produce 

 seeds; the others 

 abort at differ- 



FIG. 69. Development of flowers of Ihe Cauliflower. 



set, anterior sepal; sp, posterior sepal; si, lateral 

 sepal ; />, petal; e, long stamen ; ec, short stamen ; 

 o, ovary. A, very young flower with only rudi- 

 ments of two sepals; B, flower with rudiments of 

 four sepals ; C, older flower with rudiments of 

 petals; D, still older flower with rudiments of 

 stamens and ovary. (The flowers A D are steen 

 from the nde. In' the figures C and D the lateral 

 sepal has been removed.) E, flower seen from 

 behind; the posterior sepal has been removed. 



ent stages. Most of these remain in a very primitive 

 stage and do not develop sepals ; but, scattered 

 among them, may be found more fully developed 

 flowers, so that the same plant presents almost 

 every possible stage of flower development. 



The orgaaogeny of these flowers is quite like 



