1SP7 J 



SOMti XKW HOOKS 277 



The Nectaries of Flowers 



Beitjrage zttk Kenntnis her Seftalnectarien. By J. Schniewind-Thies. 8vo, 

 pp. 87, with 12 plates. Jena : Gustav Fischer, 1897. Price, 15 marks. 



Tins volume, with its largo well-spaced text and its beautiful supply 

 of nicely lithographed plates, including 266 figures, once more brings 

 home the fact of the extreme specialisation of present-day science. 

 It is surprising to know that Mr Gustav Fischer can find it worth 

 while to publish at fifteen shillings an independent work dealing 

 with a special kind of simple honey-secreting tissue, and containing 

 about as much matter (if we except the plates) as half of a single part 

 of our Linnean Society's Journal. 



Septal nectaries are the honey-secreting layers found, sometimes 

 on the outer surface of the ovary, but generally in the walls separating 

 the ovary chambers, in many genera of Liliaceae and other petaloid 

 monocotyledons. They have attracted the attention of various 

 botanists during recent years, and we could add to the references to 

 papers cited in footnotes by Mr Schniewind-Thies. The author gives 

 an account of the structure and position of the nectaries in genera of 

 Liliaceae, Amaryllideae, Scitamineae and Bromeliaceae, and dis- 

 i inguishes seven groups. In the simplest the secretion is effected by the 

 epidermal cells of the whole exterior surface of the ovary, from its base 

 to the origin of the three style-arms. The only examples given of this 

 are in two species of Tofieldia, one of the simplest genera of Liliaceae. 

 In the second group a " double nectary " is found, secretion occurring 

 on the surface of the ovary in three furrows lying along the septa, and 

 in three slits which permeate the separating walls of the- carpels. Ex- 

 amples are found in Yucca and Agapanthus. In the third group there 

 are no superficial glands, secretion occurring only in true septal slits as 

 in Funlia and species of Allium. Where the ovary is only partly 

 superior a double nectary may occur in the upper part and internal 

 ones only in the lower, as in Haivorthia and Urginea, or only in the 

 inferior part, as in Phormium and other Liliaceae, where a further 

 complication ensues in lateral branching of the slits and strong 

 development of vascular tissue in their vicinity. Where the ovary is 

 wholly inferior, as in Amaryllideae, Irideae and Scitamineae, and some 

 Bromeliaceae, secretion is confined to three septal slits, or occurs also 

 in three outer furrows at the thickened style-base. In Bromeliaceae, 

 with a superior or half-inferior ovary, the most complicated arrange- 

 ment is found, since, besides the double nectary as described for the 

 second group, there are also three internal glandular surfaces pene- 

 t rating the dorsal suture of each carpel, and opening upwards into the 

 ovary-chamber. Thus, it is suggested, increased complication in the 

 form of the nectary accompanies a similar change in final com- 

 plexity. In the second part of the paper the histology of the secreting 

 cell and the part played by the various constituents of protoplasm and 

 nucleus are discussed. In conclusion, we must again refer to the great 

 number of excellent drawings, which add greatly to the interest of a 

 communication consisting largely of somewhat detailed structural and 

 histological descriptions of individual cases. 



