43 



14. Flowers showing the persistent operculum. E. hmmatoxyloh Maiden, cultivated Botanic Gardens, 



Sydney. 



15. Flower showing the persistent operculum. E. fioifolia F.v.M., cultivated Botanic Gardens, Sydney. 



The same has also been observed in E. calcphylla R.Br. 



In these cases (and it has been observed in other species, see Part LVIII, p. 492), it 

 will be observed that the calyx-tube has continued to grow, leaving the operculum in arrested 

 development, adherent to the calyx-tube in the manner of a hinge. 



Sepals and Petals. 



16. Comparatively young buds of E. tetragona F.v.M., showing oil-glands (dots) and also faint lines of 



demarcation indicating the margins of petals. Lynburn, Alexander River, Western Australia 

 (H. P. Turnbull). 



17. This calyx indicates clearly the partial division into sepals (E. tetradonta F.v.M., Port Darwin, Northern 



Territory, Nicholas Holtze). It shows a bud free from insect action, and the raised tubular 

 staminal ring behind the sepals. We have in this specimen something more than " a distinctly 

 toothed calyx," as originally remarked by Robert Brown. 



E. tetradonta F.v.M., Bathurst Island, G. F. Hill, No. 466. See figs. 18a, 18b, being plan 

 and elevation of a bud. (Compare also figs. 2 and 3a, Plate 185, Part XLV.) 



Figs. 18a and 18b represent a bud attacked internally by insects, but externally they 

 clearly demonstrate certain morphological characters. They not only show the young calyx 

 separated into its sepals, but also the petals fused into an operculum. The four petals' are 

 partly united, but not perfectly so, for the demarcation lines are still present, which indicate 

 the original line of cleavage of the petals before metamorphosis took place. This seems to indicate 

 that at one time the petals of this species were free and valvate in the bud, with a thickened keel 

 or raised line down the centre, but somewhat thicker towards the. top. (I am aware that in the 

 Myrtaeese the petals are very much imbricate in the bud. It may be that in the process of fusion 

 of the petals the overlapping or imbrication has become obliterated, or is represented only by a 

 thickening.) 



The buds at this stage also show the sutural line of the operculum, which indicates that the 

 petals were deciduous in a very early state. 



Raised lines indicating the shape of the opercula are to be seen in at least two other 

 species of the Eudesmiese, e.g., E. erythrocorys, fig. 2/, Plate 184. See also its presence in 

 E. tetragona, as shown in fig. 16. Operculum fairly thin, hemispherical, copiously clotted with 

 somewhat prominent oil-glands, and marked by four very fine lines which are sometimes only 

 discernible with the aid of a lens, but often are much more distinct. 



The less closely-related E. pyriformis also shows these raised lines, e.g., figs. 16, 4c, Plate 75, 

 and figs. Id, ih, Plate 76. In these cases, although there are more than four ribs, there are four 

 principal ribs. See also fig. 6a, Plate 75, of E. piriformis var. minor, which is E. pachyphylla, 

 as shown in Part XLI, figs. 1-3, Plate 171. 



Although in the previous examples we have been dealing with the evidence of jnetals in 

 the operculum, it is proper to suggest that, in some cases, the ribs or wings in the calyx-tubes 

 indicate the lines of demarcation of sepals. For example : — 



" Eudesmia (tetragona) . . . differs from Eucalyptus solely in, having a striated 

 operculum placed within a distinctly toothed calyx, and in its filaments being collected into 

 bundles. The operculum in Eudesmia, from the nature of its stripe, and their relation to the 

 teeth of the calyx, appears to be formed of the confluent petals only; whereas thai; of Eucalyptus, 

 which is neither striated nor placed within a distinct calyx, is more probably composed, in several 

 cases at least, of both floral envelopes united. . . ." (Robert Brown, in " Flinders's Voyage," 

 1814.) 



In Part. LVIII I promised to discuss the above two sentences when a figure or figures of 

 operculum were available, and when discussing the affinities of the Eudcsmiea?. 

 G 



