PRINCIPLES 



OF 



PLANT-TERATOLOGY. 



IV. THE FLOWER, 



As was pointed out in the first volume, we may 

 regard the factors of simplification and reduction as 

 having played a large role in the process of evolution 

 of plant structures. The "flower," using this term in 

 its broadest sense to include all specially modified 

 portions of the axis on which sporophylls and accessory 

 organs are aggregated for purposes of reproduction, it 

 is best to regard as the final stage in the modification 

 of a leafy shoot. We may imagine that the axis of the 

 shoot became greatly shortened by reduction in length 

 or obliteration of the internodes, while the leaves, many 

 of which were probably at once green assimilating 

 organs and sporophylls, became greatly reduced in size 

 and complexity of organization, and modified in texture 

 and colour. A leafy fern-shoot may have become a 

 cone, which probably in its turn became still further 

 modified into a typical " flower," in the more restricted 

 sense of the term. Although it is more than probable 

 that the Angiospermous flower was derived in the past 

 from a cone-like structure, we know absolutely nothing 

 as to the nature of the plants which bore such a cone. 



The consideration of abnormal structures will include 

 not only the "flower" of the Angiosperms, but also the 



VOL. II. 1 



