;>2 



THE CASUARINAL DIVISION. 



further argument for placing Euphorbiacece as the polypetalous form of Artocarpece, Morece, Urticacece, and their allies, I would suggest that it is certain that all the larger apetalous families have, 

 and very distinctly, their polypetalous forms, and if Euphorbiacece are not the polypetalous form of these families they would be without any adequate representatives, which would be a deficiency 

 that could not be accounted for ; or, if this should be doubted, it may at least be said that a greater degree of affinity exists between them and Euphorbiacece than between them and any other 

 polypetalous family, as they agree in being always unisexual. Cecropia among Artocarpece scarcely differs, either in structure or habit, from Euphorbiacece. 



In Buxus the raphe is dorsal, as Prof. Agardh has observed (Theor. Syst. Plant p. 292, & PL XXII., fig. 1 & 2), which is an anomaly the more remarkable because in all the nearest allies of 

 Euphorbiacece the raphe in pendulous ovules is next the placenta. Corema and Ceratiola are, however, so near Buxus that Empetracece might be regarded as a section of Euphorbiacece, which 

 may be sufficient to explain this unexpected exception ; or, possibly Buxus with Simmondsia and probably Pachysandra may, with Empetracece, form a distinct family. 



Empetraceje. 



A minute and extended examination of this family leads to the conclusion that their nearest affinity is with Euphorbiacece and that their resemblances to Ericacece, such as the cohesion of 

 the pollen grains in Oakesia Conradii, which are combined in fours (Mem. Americ. Acad. New Ser. vol. III., Tab. I., fig. 5),* consist of analogies common to families which are widely separated. 



In all the genera there are bracts surrounding the base of the flower, besides that which subtends the flower itself, out of the axil of which it springs, and unless this is taken into account 

 it would be impossible to arrive at any satisfactory conclusion with regard to the nature of the floral envelopes. These bracts are 1, 2 or 3, and the flowers of each genus are otherwise so different 

 as to require a separate notice before any inference as to the nature of the floral envelopes can be safely made. 



In Empetrum nigrum the male flower has, besides the axillary bract subtending it, two lateral bracts, one on each side of it ; these are strictly foliaceous, having occasionally leafy buds in 

 their axils, but I am satisfied they exist only in Empetrum itself, the inflorescence in the other genera (where two whorls of floral envelopes at most are present) being too crowded to allow them 

 to develope. The succeeding whorl consists of three bracts which look like an external row of sepals, but as one of them is often wanting, and when present is only a rudiment, it is much 

 more probable that they are bracts ; — and when it is recollected that the three sepals above them (which are alternate with them) are closely approximated at their bases and slightly imbricated, 

 I believe there can be no doubt that they are only bracts. It being admitted that the three sepals above these bracts are the true calyx, which I believe is the prevalent opinion, it appears to 

 follow that the remaining whorl, which consists of three small petaloid bodies alternate with the sepals, would be true petals, but a comparison with Ceratiola and Corema makes it much more 

 probable that they are a second row of sepals like those which occur in Euphorbiacece. The three internal sepals are so far separated at their bases, that the stamens appear at first sight as if inserted 

 between them, but they are slightly internal to them as in Ceratiola ericoides. As thus understood the male flower agrees with that of Phyllanthus and other genera of Euphorbiacece, where the 

 sepals are six and the stamens three. The female flower differs from the male only in the absence of stamens. The stigmas are spreading and 2-ridged on the upper surface from being furrowed 

 and are sometimes more or less bifid. 



In the Kew Herbarium a note is added by a donor, stating that the flowers sometimes become hermaphrodite. 



Ceratiola may be regarded as a reduced form of Empetrum, the external and internal sepals although only two each, being much like those of Empetrum in that the external pair are 

 imbricated while the internal pair are only closely approximated ; and although the ovary is only 2-celled, the stigmas are almost as numerous, the two belonging to the fertile carpels being much 

 larger. The axils are 2-flowered from the suppression of the central bud, a rudiment of which remains, and the first two lateral bracts, which in Empetrum sometimes have buds in their axils, are 

 entirely wanting. In C. ericoides the male flower has only one bract (besides the secondary axillary bract) which is directly posterior, and it is larger than the succeeding sepals to which it is 

 external, at its insertion quite enclosing them. The external pair of sepals are placed anterior and posterior, and the posterior of the two is consequently directly opposite the bract, and therefore 

 the bract (as I regard it) cannot be a part of the calyx; they are, although the anterior one almost encloses the posterior, much narrower than the bract, and are quite opposite each other.f 



* Tn Epacrideai the pollen sometimes consists of three connate grains. 



t Dr. Klotzsch's description of Ceratiola agrees with mine so far, as that he states that the inner whorl of floral envelopes consists of two scales which he regards as petals, but as he does not take into consideration the relative position 

 of the external floral envelopes, it is perhaps partly different on that account. 



