ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 779 



Ufera and several other species, Dsemonerops melanochsete, Hyopliorhe indica, 

 Seaforthin elegans,Bactris sefrsa, CJiamsedorea elegansanA two other species, 

 Chamseicps humilis, Livistona australis, Bhapis flabelliformis, and iu Carlu- 

 dovica palmata (Pandanacefe). 



The leaf of all palms originates on the cone of growth as a circular wall 

 of unequal height, not completely embracing the cone at its lower part, but 

 which becomes closed ])y subsequent growth, and forms at this region the 

 origin of the sheath. At the higher jjortion of the cushion, which sub- 

 sequently becomes the rachis, a lamina is formed at an early period, which 

 has the form of a cap, and which has the same origin in ferns with both 

 pinnate and digitate leaves. The rudiment of the lamina is visible in a flat 

 cushion -which runs obliquely down the rudiment of the rachis. In the 

 species with pinnate leaves the rudiments of the pinnae are unsymmetrical 

 on the two sides of the rachis. At a very early period in all fomilies of 

 palms, furrows make their appearance on both the upper and under side 

 of the leaves, vertical in the digitate, horizontal in the pinnate species, 

 which develope into fissures. In an early stage the lamina of all palm- 

 leaves is therefore perfectly continuous; the alternation of these furrows 

 with cushions gives an appearance which has been erroneously ascribed by 

 previous writers to a folding of the lamina. 



The variations in different species are described in detail with regard 

 to the vernation, the mode of separation of the segments of the lamina, and 

 the unfolding of the leaf. The so-called " ligula " occurs in all palms 

 with digitate leaves, but varies greatly in size. It is not present in the 

 digitate leaves of C'arludovica. 



Stipular Sheath of Polygonum.* — Herr A. Y. Grevillius describes the 

 structure of the stipular sheath or ochrea in several species of Polygonum, 

 some of terrestrial, some of aquatic habit, and suggests that its very 

 unequal development in the different species is connected with their 

 different biological conditions. 



Turgidity of Petals.f — Prof, O. Beccari has noticed the existence of 

 water iu a state of strong tension in the cells of the thick petals of Magnolia 

 Yulan, Nerium Oleander, and Camellia japonica, and iu the leaves of JRumex 

 Lunaria, shown by the appearance of a little cloud of vapour when the 

 epidermis is removed. 



Spike-like partial inflorescence of the Rhyncosporeee.l — According 

 to Herr L. Celakovsky, the Ehyncosporete and Gahniese differ from the 

 other sections of the Cyperacefe in the divisions of the inflorescence not 

 being true spikes, but spike-like cymes consisting in most instances of only 

 two or three flowers. 



Zygomorphy of Flowers. § — Prof. F. Delpino describes the various 

 degrees of zygomorphy which occur in different flowers, and classifies the 

 forms of flowers as follows in relation to their mode of pollination. 



Omnilateral actinomorpliic are among the least specialized flowers, and 

 are adapted to the visits of insects of various kinds ; such are those of 

 Ranunculus, Bosa, Poientilla, Pceonia, Nymphaea, &c. Sexlateral actino- 

 morpliic flowers, such as those of many species of Lilium, are specially 

 adapted to the visits of Sphyngidae, while those which are quinquelateral 

 and actinomorphic, such as Aquilegia and the Apocynaceae and Asclepiadeas, 



* Naturf. Studentsallsk. Upsala, Dec. 7, 1886. See Bot. Centralbl., xxx. (1887) 

 pp. 254-5, 287-8, 333-5. Cf. this Journal, ante, p. 430. 

 t Malpighia, i. (1887) p. 420. 



X Ber. Deutsch. Bot. Gesell., v. (1887) pp. 148-52 (1 fig.). 

 § Malpighia, i. (1887) pp. 245-62. Cf. this Journal, anfe, p. 266. 



