EUCALYPTUS EXIMIA. 



and more lustrous outer lid, and by the larger fruits ; the seedling state may also be different. 

 Although called a Bloodwood-tree it differs widely from E. corymbosa, not only in some of the 

 characteristics of its flowers and fruits, but also in foliage and bark, the latter being of more scaly 

 texture and also smoother outside. 



The lid of B. eximia affords excellent material for tracing the metamorphosis of a calyx into 

 a corolla, and gives in this genus additional evidence for estimating the nature of the opercular 

 organ ; it shows that the ordinary lid of Eucalyptus-flowers must be regarded as calycine, though 

 it may consist of two layers, the outer of which, when it occurs, being sometimes fugacious and 

 occasionally minute. The homogeny of the opercular with the tubular portion of the calyx is 

 clearly evidenced by the species of Eucalyj)ts pertaining to the series of E. corymbosa, as pointed 

 out previously 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. Nevertheless 

 the Ud of Eucalyptus may in some instances be regarded as externally calycine and internally 

 petaline ; this view obtains complete confirmation by the sj)ecies now before us and by a few other 

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

 may readUy be drawn off from the thinly cartUagineous 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 fiower 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. rostra ta 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 

 Eucalyptus and some other myrtaceous genera by Pleurocalyptus (Brogniart et Gris in nouvelles 

 archives du museum iv. 20-21, pi. 5), 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 Encalypts is established, 

 just as in a similar manner the petals of several species of Eugenia, belonging to the section 

 Acmene or Syzygium, become very much reduced in dimensions and also sometimes connate. It 

 is different with Angophora, which genus finds habitual repetitions in some Eucalypts, for instance 

 E. setosa and E. aspera ; here the calycine lobes assume the apj)earance 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-teeths, developed in E. tetraptera and 

 more distinctly still in E. odontocalyx and E. tetrodonta, the lid of aU being calycine also. 



Explanation of Analytic Details. — 1, an unexpancled flower, the lid lifted ; 2, longitudinal section of an unex- 

 panded flower ; 3, some of the oviter stamens expanded ; 4 and 5, front- and back-view of an anther with part of its 

 filament ; 6, style and stigma ; 7 and 8, transverse and longitudinal section of a fruit ; 9 and 10, fertile and sterile seeds ; 

 11, portion of a leaf ; all figures magnified, but to various extent. 



