454 Ml". J. Miers on the genus Cathedra. 



Choretrum ; these are stated by Mr. Brown (Prodr. p. 354) to be 

 4-locular and 4-valved, but although correct to a certain extent, 

 this requires some explanation : their form, which is somewhat 

 peculiar, is tolerably well represented in Endlicher's ' Icono- 

 gi-aphia,^ tab. 45 ; the four rounded lobes there shown consist of 

 four distinct pollen- cells, quadrately placed at right angles to the 

 filament, round a short central connective, and inclosed by thick 

 crystalline walls, as in Cathedra : but here, the apices of the cells, 

 which point towards the style, at first open by a minute pore, 

 close to the apical summit of the connective, when by the gra- 

 dual contraction of the walla, the margins, beginning at these 

 pores, recede and sepai'ate from it, showing a somewhat cruci- 

 form opening in the summit, and leaving the connective in the 

 central space like a short columnar receptacle, around which the 

 pollen-grains of the four cells remain agglutinated : there exist 

 in reality no sutural slits, so that the anther can hardly be said 

 to be 4-valved. 



I have endeavoured to detect some similar mode of dehiscence 

 in the anthers of Cathedra, which possess precisely the same 

 structure, but in vain, although we might expect to find them 

 discbarge their pollen, as those of Choretriwi are found to do. 

 It may be well here to adduce the very analogous instance of 

 similar structure in Myzodendron, which will be touched upon at 

 greater length on some futiire occasion, and which has been very 

 beautifully demonstrated by Dr. Hooker in his admirable ana- 

 lytical details of that genus in plates 104 and 105 of the ' Flora 

 Antarctica'; in a subsequent memoir I shall compare the cu- 

 rious analogies observable in these instances, as they will be found 

 to offer a strong bearing upon the affinities of Cathedra. 



The anthers of Viscum will also serve to throw some light 

 upon this subject ; these have been described by all preceding 

 botanists as being formed of numerous, aggregated and di- 

 stinct cells, each filled with pollen-grains, and which dis- 

 charge these fertilizing particles by as many distinct pores, in 

 a manner that has been described and clearly delineated by 

 Richard in the 'Ann. Mus.' xii. p. 296. tab. 27. fig. 3. M. 

 DeCaisne, in a learned memoir on the development of the 

 pollen in Viscum album (Mem. Acad. Bruxelles, vol. xiii.), details 

 the mode of growth of its anthers, and exhibits highly magnified 

 transverse sections of the same in their dififerent stages, but does 

 not give a single vertical section, nor any description or drawing 

 of the anther in its mature state : we may therefore conclude that 

 he coincided with the description of Kichard, in regard to its 

 being composed of an indefinite number of distinct aggregated 

 pollen-cells ; he seems indeed to confirm this struct""e, for in 

 his memoir just quoted, tab. 1. fig. 3, he shows a transverse sec- 



