ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 219 



Cross-Pollination and Self-Pollination. — The late Herr P. Knuth * 

 describes the mode of pollination of several Javanese species of Musxsenda, 

 which is effected by Lepidoptera. In one instance the butterfly, with a 

 proboscis 27 rum. long, obtains the honey from the bottom of the long 

 tube without seating itself on the flower. 



Dr. F. Ludwig f gives a detailed description of the relative position 

 of the parts, and the changes in colour of the perianth, of the strongly 

 proterogynous Helleborus foetidus, which all piomote cross-pollination 

 by bees, making the inflorescence more attractive from a distance. 



Prof. G. v. Lagerheim J describes the adaptation to cross-pollination 

 in the flowers of Brachyotum ledifolium, a shrub of Ecuador belonging 

 to the Melastomaceee. It appears to be pollinated almost entirely by two 

 species of humming-bird, attracted by the insects which feed upon the 

 nectar. The structure of the flowers is such that it is hardly possible 

 for the pollen to be carried to the stigma by the insects themselves ; 

 while self-pollination seems altogether excluded. Other ornithophilous 

 plants from Ecuador are also mentioned by the author. 



Mr. R. C. McGregor § points out the adaptations in the flowers of 

 the American Salvia coccinea to pollination through the agency of a 

 humming-bird, Calypte anna. 



Dr. E. Fisch || gives a variety of interesting details respecting the 

 adaptations to insect-pollination in a number of alpine and desert plants, 

 naming the class (but not the genus or species) to which the visitors 

 belong. Among alpine plants he finds, in opposition to the statement 

 of H. Miiller, that red and blue flowers on the one hand, and white and 

 yellow flowers on the other hand, occur in nearly equal numbers. 



In Vicia lathyroides, Herr E. Loew % finds an example of retrogres- 

 sion in the development of xenoganious flowers in the direction of auto- 

 gamy. Although it does not produce strictly cleistogamous flowers, the 

 monadelphy of the stamens, the absence of honey-glands, the reduction 

 of the standard and keel, all point to an adaptation to self-pollination. 



Knuth's Handbook to the Biology of Flowers.** — The most recent 

 part of the late Dr. P. Knuth's Handbook comprises the remaining 

 orders of Dicotyledons, commencing with the Lobeliaceee, as well as the 

 Monocotyledons and Gymnosperms. All recent observations on the 

 mode of pollination of the species belonging to these orders are referred 

 to, whether by the author or by other observers, and a copious biblio- 

 graphy is appended. A third volume, referring to extra-european 

 species, remained unpublished at the time of the author's lamented 

 death ; but arrangements have been made for its publication. 



* Dodousea, 1899, 8 pp. and 7 figs. See Beiheft z. Bot. Centralbl., viii. (1899) 

 p. 509. t Bot. Centralbl., lxxix. (1899) pp. 153-9 (3 figs.). 



; Bot. Notis., 1899. pp. 105-22 (1 pi.). See Bot. Centralbl., lxxx. (1899) p. 78. 



§ Amer. Naturalist, xxxiii. (1899) pp. 953-5 (3 figs.). 



|| Biblioth. Bot., Heft 48, 61 pp. and 6 pis. 



% Flora, lxxxv. (1899) pp. 397-403. 



** ' Handb. d. Bliithenbiologie,' vol. ii. pt. 2, Leipzig, 1899, 705 pp., 210 figs., and 

 1 portrait-plate. Cf. this Journal, 1 898, p. 647. 



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