THE AMERICAN BOTANIST. 91 



tips of the sepals. The apple is, in tact, an enormouslj^ 

 enlarged torus or receptacle that has grown up around 

 the pistils, bearing the sepals on its apex. If one examines 

 a rose fruit he will find the rose apple not quite closed at 

 the top and so be able to form an idea of the probable 

 evolution of the apple from some rose-like ancestor. The 

 pulp that surrounds the paipery envelope enclosing the 

 rose seeds is a succulent receptacle. In the wild crab the 

 envelope surrounding the seeds is hard and compact, so 

 that the flesh3^ receptacle separates readilj^ from it. It 

 was formerly believed that in cases like those just men- 

 tioned, the parts called the receptacle were reallj^ parts of 

 the cah'x. Thus when the parts enclosed the ovary the 

 latter was said tohe inferior, while a superior ovaryis one 

 free from the caWx. These terms are still in common use. 

 Like the petals, the sepals assist in effecting pollina- 

 tion. They are often produced into spurs containing nec- 

 tar and maj' also be of such shape and position as to aid 

 in guiding the insect to the hone^^-glands. In apetalous 

 flowers with brightly colored sepals they must also serve 

 to attract insects in all of which they show their close 

 relationship to petals. 



THE EUCALYPTUS. 



BY DR. WILLIAM WHITMAN BAILEY. 



THE gigantic gum-trees or stringj^ barks, characteristic 

 of Australian forests, belong to the genus Eucalyptus 

 of the great fainily Mj^rtacejE. Some 150 species of these, 

 at least, have been described. The accounts, however, are 

 most unsatisfactory and the specific discriminations often 

 unreliable from the fact of the extreme variability of ap- 

 pearance assumed by individuals at different ages or peri- 

 ods of growth. Thus the stem, which in youth may be 

 square, later become cj-lindric or columnar. The foliage, 

 even on a particular tree, may show a variety as great as 

 our sassafras. We may thus find on one plant oblong, el- 

 liptical, lanceolate or scj^the-shaped leaves. 



Australia is, so to speak, their capital ; some are found 



