' 



OF r XHE CTSTOCABPS OF CATENELLA OPUKTIA. 73 



guished by its wrinkled appearance. The surface is raised into 

 a number of small mounds, each corresponding to what might 

 perhaps be termed a nest of pollinoids. The ripe ramulus con- 

 tains 30 to 50 such nest3. The wall of each nest is composed of 

 ordinary peripheral cells; but those forming the base of the 

 nest are smaller and more rod-shaped. From these in turn arise 

 the rather ovate pollinoids or spermatia which are shed into a 

 cavity beneath the cuticle, escaping by a rupture in the mem- 

 brane (PI. XIII. figs. 5, G). 



Cystocarps. — The cystocarps are borne on the erect branches, 

 every articulation (in my plants) bearing one or two cystocarpic 

 ramuli. I have occasionally come across specimens with two 

 cystocarps placed headways on the same frond ; but this is rare. 

 Sometimes the cystocarp is the terminal articulation itself*. 

 Each ramulus is nearly spherical aud is shortly stalked, and 

 easily distinguished, even when young, by the clear border which 

 surrounds it, and by a fringe of delicate colourless short pro- 

 cesses apparently arising from the interior, piercing the border 

 and projecting at right angles to the surface. A transverse 

 section of a mature cystocarpic ramulus under a low power 

 (x 100) shows, from without inwards, 1st, the clear hem already 

 mentioned and colourless processes (though not nearly so nume- 

 rous nor so distinct in the mature as in the young condition) ; 

 2nd, a tolerably broad zone of peripheral cells deeply coloured 

 and arranged in radiating rows quite similar to the ordinary peri- 

 pheral zone in the vegetative frond ; 3rd, a zone of interwoven 

 filaments, broader or narrower according to the stage of develop- 

 ment; 4th, a broad zone of carpospores— large, deeply coloured 

 cells, amongst which may be seen branched filaments uniting the 

 zone of filaments with (5th) a small medulla of shorter inter- 

 woven cells. In the very young stage the carpospores are entirely, 

 absent, and the third zone and medulla are continuous, the cysto- 

 carpic nature of the ramulus being indicated at that stage merely 

 by the clear border and its processes. If a longitudinal section 

 be made of a young cystocarpic ramulus, the exterior will be 



During a recent visit (June 1891) to the locality where I first obtained 

 C. Opuntia with cystocarpic fruit, I was fortunate enough to secure fresh material 

 again bearing cystocarps. In many of the specimens which I gathered the erect 

 fronds bore three, four, or even five cystocarpic ramuli ; while on one specimen 

 a single articulation gave origin to no less than nine such ramuli disposed all 

 round the frond* . 



