1910] _  HOYT—FERTILIZATION IN FERNS 361 
revolving on their axes, as previously described; they then go forward. 
This movement usually results in their sates os toward the arche- 
See ee Segoe 
Son 
4 
10. 2 
Fic. 1.—Spiral courses of sperms: a, thick ink; }, thin ink; c, water. 
Fic, 2.—The position of the salt crystal is indicated by #. 
Fics. 3-12.—Various responses of sperms. 
gonium, but not directly toward it; and their subsequent orientation 
and entrance into the archegonium is attained by a series of gradual 
Swingings toward the archegonial mouth as they go forward. Most 
Sperms, however, react less immediately and attain their orientation 
