282 PKOCEEDINGS OF SOCIETIES.
some places. Altlioiioli not notiopcl in any list of Greenland plants, it oceurred on pieces of lava brought from Greenland as ballast, and used in the Botanic Garden for rockwork. G. pntinosa, Wils. ms., was de- tected in Dr. Greville's herbiirium. It was collected in 1847 in the King's Park, Edinburgh (see Journ. Bot. Vlll. 205). G. anodon, B. and Seh., was first discovered in Britain by Mr. W. Bell, on Arthur's Seat, in 18(i9. G. orbicularis, B. and Sch., was first detected in Britain by Mr.
Sadler, on Arthur's Seat, in the same year. J. Birkbeck Nevins, " On
the Changes which occur in Plants during the Ripening of Seeds." This paper consisted of a number of unconnected remarks on changes in the direction of the pedicel after the expansion of the flower. In Digitali-H and other Scroplmlarinece the seed-vessel becomes erect, otherwise the seeds would fall out before they are ripe ; Lim.osella is an obviously ex- plicable exception. In plants such as Cari/ophi/llacece and liuninicnlaceee, which flower during summer, the pedicel is usually erect. In Helhboras it is drooping after flowering, the persistent floral envelopes protecting the fruit. The same thing is observable in many autumnal flowering plants, such as Tagetes, where the involucre in the drooping inflorescence roofs over, as it were, the fruits. The author concluded by propounding his views as to tlie morphology of Cruciferous fruit. The replum and placentas he regarded as a continuation of the axis bearing two terminal leaves, which, becoming reflexed, adhere to the axis, and are, in fact, the valves of the capsule ; when the ca|)sule ripens the adhesion relaxes, and
the leaves uncoil. Professor Wyville Thomson remarked that the facts
detailed in the paper were familiar enough as a matter of description, but were interesting in a teleological point of view. He doubted whether the explanation of the fruit in Vrucifvrcc would find much acceptance amongst
botanists. Professor Thiselton Dyer, " On the Minute Anatomy of the
8tem of the Screw-pine {Vandanus utilis)." Except that the tissues are less indurated, the general structure of the stem and the arrangement of the flbro-vascular bundles resembles that met with in Palms. The bundles, however, are somewhat remarkable, from containing vessels which belong to the scalariform type. In a transverse section these bundles are seen to become smaller towards the circumference and more condensed, forming a well-defined boundary to the narrow cortical portion of the stem. The Ijundles are, however, continued through the cortical portion, but are reduced to little more than a thread of prosenchyma. In the cortex there are numerous large cells, containing raphides ; these also occur in the rest of the stem, but are less frequent. Crystals of another kind are found in connection with the fibro-vascular bundles. These are contained each in a squarish-shaped cell, forming part of a string or chain. A number of these strings are distributed round the circum- ference of each fibro-vascular bundle; they are especially abundant in its cortical continuation, as they do not suffer a degradation proportionate to that of the other constituent tissues. This peculiar arrangement of crystal-bearing cells seems probably unique. The crystals are four-sided prisms with pyramidal apices. They are almost certainly composed of calcium oxalate, though they are too minute and isolated with too much
difficulty to allow of their satisfactory examination. Professor Dickson
was much struck with the peculiar arrangement of the bundles in the dia- gram ; proscncliyma mixed with vessels was shown both upon their inside and outside. He was doubtful as to Professor Thiselton Dyer's cxplana-
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