Contributions to our Knowledge of the 
Physiology of the Spermatozoa of Ferns. 
BY 
A. H. REGINALD BULLER, B. Sc. (Lond.), Ph. D. (Leip.). 
Contents 
PAGE 
I. CHEMOTAXIS. 543 
Introduction . . ..543 
Material and methods ..549 
Results . . . . . . . . . . 552 
The dissociation theory and chemotaxis ..... 562 
General points . . . 569 
II. THE WITHDRAWAL OF WATER FROM SPERMATOZOA 572 
III. LENGTH OF THE SWARM-PERIOD .... 575 
IV. THE STARCH IN THE VESICLE .... 579 
V. SUMMARY OF THE CHIEF RESULTS . . . 581 
I. Chemotaxis. 
Introduction. The reaction of free-swimming organisms to 
chemical stimuli by alteration in the direction of movement is 
known as chemotaxis. This phenomenon was first generally 
investigated by Pfeffer 1 . Its results, although not recognized 2 
as such, had however previously been observed by Stras- 
1 Locomotorische Richtungsbewegungen durch chemische Reize. Untersuchungen 
aus d. Bot. Inst, zu Tubingen, Bd. i, p. 363, 1884. Ueber chemotaktische Bewe- 
gungen von Bacterien, Flagellaten u. Volvocineen. Ibid., Bd. ii, p. 352, 1888. 
2 Pfeffer, Ber. d. D. Bot. Gesellschaft, 1883, p. 524. 
[Annals of Botany, Vol. XIV. No. LVI. December, 1900.J 
O O 
