274 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Distribution of the Fruits of Compositse * — Herr M. Kronfeld 

 describes the various ways in which the mature pappus serves to 

 disseminate the fruits of the Composite. The most common mode is 

 by the finely divided hairs of the pappus itself forming a parachute. 

 In the Cynarefe the pappus-hairs are united together by their base 

 into a ring, and the whole becomes detached from the achene by the 

 slightest pressure. This appears to be a contrivance for enabling the 

 fruit to reach the ground after travelling a short distance. In some 

 species the withered flower acts the part of a pappus. A second 

 mode of dissemination is by means of teeth attached to the hairs of 

 the pappus, by which they become attached to the skins of animals, 

 and thus carried away. A third mode is by running water, the 

 pappus forming a floating apparatus, often greatly facilitated by a 

 bubble of air being retained by the hairs. 



Epidermal System of Cactacese.t — Herr H. Caspari describes 

 two kinds of spines in the plants belonging to this order; in one the 

 epidermal cells which surround the sclerenchymatous bundle are 

 cylindrical or prismatic in the upper, flat and imbricate in the lower 

 part of the spine ; while in Mamillaria the terminal cells are chiefly 

 prosenchymatous, the basal parenchymatous. The occurrence of these 

 two kinds of spine may be used as distinguishing characters of 

 species, but not of genera. The Cactacese are specially adapted for 

 their dry habit, by the strong cuticularizing of the cuticle, the great 

 development of hypoderma, and the structure and distribution of the 

 stomata. 



Anatomy of Leafless Plants. | — Herr T. Sghube describes the 

 arrangements by which plants that have no or very few leaves are 

 able to carry on the functions of assimilation. This is effected by an 

 unusually abundant development of parenchyma in the axial organs, 

 and by a diminution of the means of transpiration. 



Flowers of Figs.§ — Dr. F. Ludwig reports some recent observa- 

 tions of cases where fertilization is effected by insects which deposit 

 their ova on the flowers. Eiley || has shown how the yucca-moth, in 

 depositing its ova within the flowers of the Tucca, accomplishes the 

 fertilization, and how the few seeds which the larvae devour in their 

 cradle are unimportant in such richly filled ovaries. 



Graf zu Solms-Laubach ^ has observed a complicated arrangement 

 in various species of figs. Besides the male flowers, two entirely 



* SB. K. Akad. Wiss. Wien, xci. (1885) (1 pi.). See Oester. Bot. Zeitschr., 

 XXXV. (1885) p. 436. 



t Caspari, H., ' Beitr. zur Kenntniss dea Hauptgewebes der Cacteen,' 53 pp., 

 8vo, Halle, 1883. See Bot. Ztg., xliii. (1885) p. 804, 



t Schube, T., • Beitr. zur Kenntniss der Auat. blattarmer Pflanzen, mit 

 besonderer Berucksichtigung der Genisteen,' 28 pp. (2 pis.), 8vo, Breslau, 1885. 

 See Bot. Ztg., xliii. (1885) p. 805. 



§ Biol. Centralbl., v. (1885) pp. 561-4. 



II Trans. Acad. Sci. St. Louis, 1875, 1878. Proc. Amer. Assoc. Adv. Sci., 

 1880. 



t ' Domestikation und Vaterland des gewohnlichen Feigenbaums,' Gottingen, 

 1882. Cf. this Journal, ante, p. 99. 



