490 



in these pages ; because both lid and tube are homogeneously confluent while in bud, and when their 

 severance takes place by force of extrusion of the stamens, we find the transverse line of separation not one 

 of clear dehiscence, but one of more or less irregular tearing.; nor does this rupture lead always to a shedding 

 of the lid, it being often retained during the whole time of flowering, and thrown simply back from the 

 remaining place of alligation (attachment.) Nevertheless, the lid of Eucalyptus may in some instances be 

 regarded as externally calycine and internally jietaline (corolline;) this view obtains complete confirmation 

 by the species now before us (eximia), and by a few other congeners. 



When the lid of E. eximia has been well macerated, a tender petaloid (corolloid) inner membrane 

 may readily be drawn off from the thinly cartilagineous calycine portion of the lid; this inner stratum, 

 which in nature seems often to be set spontaneously free at last, as I found this to be the case with a few 

 other congeners, produces from its centre a short descending tube, which encloses the summit of the style 

 and the stigma before the flower expands. 



Such tubule descending from the inner lid is not to be found on the operculum of the closely allied 

 E. maculata, in which species the two opercular strata are also far less dissimilar than in E. eximia, thus 

 more conformous to the occasional two of E. rostrata and the regular two of E. peltata, not to speak of some 

 others ; yet the inner may be regarded as petaline also in E. peltata-; and we would; perhaps be justified in 

 assuming that the lid of Eucalyptus calyces is formed generally by the permanent confluence of an inner 

 petaloid and outer calycoid layer. 



Additional light is shed on the structure of the lid of Eucalypts and: some other myrtaceous . genera 

 by Phuroealyptus, in which the operculum is retained on one side after the irregular transverse bursting of 

 "the calyx, similarly to what occurs in Eucalyptus corymbosa and its allies; petals are, however, conspicuously 

 developed. But in Acicalyptus and Piliocalyx the petals, although distinctly formed, are of irregular and 

 diminutive size and even somewhat coherent or concrescent, whereby some transit to the petaloid inner 

 lid of some Eucalypts is established, just as in a similar manner the petals of several species of Eugenia 

 belonging to the section Acmena or Syzygium, become very much reduced in dimensions and also sometimes 

 connate. It is different with Atigophora, which genus finds habitual repetitions- in some Eucalypts, for 

 instance, E. setosa and E. aspera ; here the calycine lobes assume the appearance of petals ; but they are 

 sessile with broad base, and only petaloid towards the margin, as to some extent in Leptospermum, Eugenia 

 and many other Myrtaceous genera ; while the five alternating points, continuous to the main ridges of 

 the calyx-tube, are. equivalent to the calyx-teeth developed in E. tetraptera, and still more distinctly in 

 E. odontocalyx and E. tetrodonta, the lid of all being calycine also." (" Eucalyptographia " under 

 E. eximia.) 



(4) " In E. Preissii, E. terminalis, E. Abergiana, and a: few. other species, the calyx is rather 

 irregularly ruptured than circumcised by a. clearly defined sutural line ; at best only the inner layer of the 

 lid could be assumed to be corollaceous, but it is closely connate with the outer stratum as usual in the 

 genus." (ib. under E. tetrodonta.) 



(5) " A narrow and elongated outer quickly deciduous operculum covers not rarely the normal 

 lid." {ib. under E. rostrata.) 



Naudin, 1891. (1) " The operculum, which is not, in my opinion, any different to the corolla of 

 which the pieces are fused congenitally, often furnishing good specific characters by their shape and 

 relative size." (Mem. ii, 13) (translation.) 



(2) '" There are in reality two superposed opercula, the exterior, attributed to the transformation 

 of the calyx, is reduced to a scarious skin, very fugacious, which caps the corolline operculum. One only 

 sees it in very young buds, for it falls early. It seldom develops as much as the interior operculum, which 

 then appears to be double." (ib.) 



Deane, 1897. " The flowers themselves have lost the power of producing petals, except as such 

 may be represented in the deciduous operculum, and this gives a still stronger hint of the whole plant 

 having become modified in the course of long ages to resist drought, whereas its closest congeners, 

 Tristania and Angophora, which have petals, are confined respectively entirely to the coast districts or to 

 damper situations on the eastern side of Australia, not having been able to penetrate very far into the 

 droughty interior." (H. Deane, Proc. Linn. Soc. N.S.W., xxii, 471, 1897.) 



