268 Sma 1 1. -Pollen-presentation Mechanism . 
Inula Helenium , Antennaria dioica , Tanace turn vulgar e } Achillea, P tar mica, 
A. millefolium , Senecio sarracenicus , Centaur ea Cyanus , (7. Jacea , (7. 6V#- 
biosa^ Cirsium arvense , Carduus crispus, Lapsana communis , and Cichorium 
1 h ty bus. 
(17) First recorded in August, 1916, v. literature cited (13). 
Acknowledgements are due to the Director of the Royal Botanic 
Gardens, Kew ; the Regius Keeper of the Royal Botanic Garden, Edin- 
burgh ; the Curator of the Cambridge University Botanic Garden ; and to 
the Curator of the Chelsea Physic Garden, for the facilities which they very 
kindly granted for the examination of living material. 
Summary. 
1. Various types of sensitive movements in the Compositae are 
distinguished. 
2 . A list of 149 species and varieties showing irritability is given 
in which the type and degree of irritability observed are recorded. 
3. Irritability was found in 64 per cent, of the species and varieties 
examined, and in all the tribes of the family except the Eupatorieae and the 
Vernonieae. 
4. Notes on special, interesting cases, such as the explosive irritability in 
the Mutisieae, and the peculiar, slow movement in the Cichorieae, are 
appended. 
Literature cited. 
1. Brown, R. : Some Observations on the Natural Family called the Compositae. Trans Linn. Soc., 
vol. xii, i8t8. 
2. Gray, A. : Notes on the Movement of the Androecium in Sunflowers. Proc. Acad. Nat. Sci., 
Philadelphia, 1884, p. 287. 
3 . Hildebrand, F. : Uber die Geschlechtsverteilung bei den Compositen. Nov. Act. Leop., 
Halle, 1869. 
4 . J u el, O. : Om pollinationsapparaten hos familjen Compositen. Svensk. Bot. Tidsk.,^ 1908, 
Bd. ii, p. 350. 
5 . Knuth, H. : Handbook of Flower Pollination. Eng. Trans, vol. ii, pp. 568 sqq. 
6. Kolreuter, J. B. : Vorlaufige Nachricht von einigen das Geschlecht der Pflanzen betreff. 
Versuchen. Dritte P'ortsetzung, p. 245. Leipzig, 1766. 
7 . Linsbauer, L., and Linsbauer, K. : Zur Kenntniss der Reizbarkeit der Centaurea- Filamente 
nebst Bemerkungen iiber Stossreizbarkeit. Sitz.-Ber. Akad. Wiss. Wien, Bd. cxvi, Abt. I, 
1907, p. 1741. 
8. Meehan, T. : On Elasticity in the Filaments of Helianthus. Proc. Acad. Nat. Sci. Philadelphia, 
1884, p. 200. 
9 . Minden, M. von : Reizbare Griffel von zwei Ardotis- Arten. Flora, Bd. lxxxviii, 1901, p. 238. 
10. Moore, Spencer le M. : Alabastra diversa . Part XII. Journal of Botany, vol. xliii, 1901. 
11 . Pfeffer, W. : Physiologische Untersuchungen. Leipzig, 1873. 
12 . Small, J. : Preliminary Observations on the Pollen-presentation Mechanism of Ardotis aspera , 
L. New Phytologist, vol. xiv, 1915, p. 216. 
: Facts and Fancies about Dandelions. Pharm. Journ., vol. xcvii, 1916, p. 157. 
13 . 
