AIU. G. EKXTHAM OX MYKTAGK.T^. 11 I 



serted on, the calyx-tube. So iu most Monoi^etala) the stamens 

 arc said to be inserted on the corolla-tube, whilst in Malvacese it 

 is the petals that are adnate to, or inserted on, the staminal tube. 

 The concretion in all these cases is theoretically the same, the di- 

 versity of expression being regulated by the difference in propor- 

 tion of the connate organs. 



There is another point in the terminology of the parts of the 

 calyx in Myrtacese which requires some fixation ; that is, as to 

 what is tube and what is limb — often a very vague distinction, 

 variously interpreted by different botanists. It is usually deter- 

 mined by outward form. AVhere a calyx or corolla is salver-shaped 

 (hypocrateriform), or simply funnel-shaped (infundibuliform), there 

 is no difficulty, the limb and tube are well defined ; in the cam- 

 panulate corolla or calyx the undivided part is called tube, and 

 the limb restricted to the lobe : but the difficulty lies in those 

 calyxes and corollas approaching to the funnel-shape, which have 

 a narrow^ tube at the base, then a dilated portion which is still 

 further exj)anded at the top ; liere the intermediate portion is by 

 some described as part of the tube, by others as part of the limb, 

 and by otliers, again, as a separate part called fauces or throat — a 

 difference of view which renders descriptions of the same corolla 

 by some French and Grerman botanists apparently irreconcilable. 

 In many flowers the expansion from the tubular base through the 

 fauces to the horizontal lobes is so gradual that we can only draw^ 

 a line at the point of division. In the calyx of Myrtacete, how- 

 ever, it has been found better to neglect outward form in this 

 respect, and to take as the line of demarcation between the tube 

 and the limb that of the margin of the aduate staminal disk, which 

 I have above alluded to as constantly distinct, — calling all limb that 

 is above that line, whether entire, lobed, or divided to the base. 



The degree of development of the calyx-tube above the ovary 

 (whether the stamen-bearing margin of the disk is close to the 

 ovary, or forms a ring more or less perceptibly or prominently 

 raised above it) has been made great use of for the distinction of 

 genera by O. Berg. It has appeared to me, however, not only to 

 be in most cases purely artificial (that is, unaccompanied by any 

 other character or difterence of habit), but frequently inappreciable. 

 Take, for instance, Berg's genus Aidomyrcia as distinguished from 

 Myrcia^ or Blume's Microjamlosa as separated from the genus or 

 section Jamhosa : by this character alone not only does each of these 

 segregrated genera include groups of species more nearly allied to 

 corresponding groups in the parent genus than they are to each 



