BOTANICAL GAZETTE. 215 



Inal color of all petals." The proofs relied upon by Professor Allen to 

 sustain this position are chiefly three. First: the earliest flowers, i. e.. 

 those of the Gymnosperms, consisted only of naked ovules and clusters of 

 stamens. Inasmuch therefore as sepals and petals are a later develop- 

 ment than stamens and carpels, they cannot be said to show a transition 

 between green leaves and the latter, as held by the Wolfian hypothesis. 

 Second: stamens show a tendency to become petaloid, as shown by such 

 flowers as Nymphcea, the Mesembryanthemums, orchids and others. 

 Third: the occasional reversion of petals to stamens as in Monarda and 

 Capsella. 



Assuming the truth of the proposition that the original petals were 

 yellow, the second and largest part of the book is devoted to showing 

 the successive stages in the color-development of flowers, viz: (1) yellow, 

 (2) white, (3) red or purple, (4) lilac, mauve, violet or blue. Examples 

 from many families are adduced to show that the most specialized flow- 

 ers of a single color are blue and the the least so are yellow. Variegated 

 flowers are still more highly developed, the ground-color being usually 

 some one of the higher series while the spots or lines are of one or more 

 of the lower colors. The occurrence of yellow or white petals in con- 

 junction with a high degree of specialization in other organs is account- 

 ed for by retrogression. "Flowers which have reached a given stage in 

 the progressive scale of coloration often show a tendency to fall back to 

 a lower stage." Green flowers (except in Gymnosperms) are explained 

 to be the degenerate descendants of more gaily colored ancestors. 

 Anemophilous green Angiosperms must therefore be considered as the 

 development of flowers. 



I have said that Professor Allen's hypothesis was plausible. It is 

 more. Because of the pleasant style of the writer and the easy explana- 

 tion he offers of those facts which he cites, it is fairly enticing. But 

 there are some things in flower coloration and teratology "hard to be un- 

 derstood" on this theory. Some of Professor Allen's arguments if close- 

 ly scrutinized, bear in themselves marks of weakness and others are so 

 strained that they have almost passed their "elastic limit." It is hard to 

 believe that amentaceous trees which appeared in the Cretaceous were a 

 later development than the Magnolia, Liriodendron and Maple, with 

 which, as far as Paleontology shows, they were contemporaneous. Fur- 

 ther, if the Qraminea? and Cyperaeen? are degenerate descendants of some 

 petaliferous liliaceous plant, it is strange that no traces of these ances- 

 tral forms were preserved, whereas in the upper Eocene beds are found 

 fossil species of Arundo, Carex. Cyperus and Poacdtes. The objection 

 that such ancestral forms as Professor Allen's theory needs did not grow 

 in places where they would likely be preserved cannot be urged because 

 the A lifunacece (some form of which he thinks was the primordial lily) 

 affect the same stations as the Cyperacece. 



The fact that stamens tend to become petaloid, instead of helping 

 the hypothesis that petals are flattened stamens seems rather to militate 

 against it. That there is a constant tendency to reversion no one who 

 believes in the doctrines of morphology will deny. It is certainly more 

 reasonable to suppose that stamens are reverting to an ancestral form 

 when thev become petaloid, as they do in numberless instances, than to 

 suppose that petals are reverting when in a very few cases they become 

 antheriferous. 



Again, upon the theory advanced how can the origin of sepals be 

 accounted for? Were the primal sepals yellow or blue? or have they 

 degenerated to a green color ? Can anyone believe that when sepals and 

 bracts become petaloid they are reverting to an older form. 



While we cannot accept as reasonable the theory advanced for the 



