r 2 Wisconsin Academy of Sciences, Arts, and Letters. 
spiral band. Guiguard remains in doubt whether a cytoplas¬ 
mic envelope encloses the nucleus of the mature antherozoid. 
In the same year, Belajeff also describes the formation of 
Hie antherozoid in Pteris, Gymnogramme and Aneimia. The 
antherozoid mother cell first develops a hook-shaped projection 
of the cytoplasm which becomes the anterior end of the anthero¬ 
zoid. Belajeff believes that the spiral form results from a 
folding in of the surface of the cell while the nucleus becomes 
stretched into a shorter parallel spiral. Belajeff describes the 
origin of the cilia from the outer surface of the spiral band. 
Strasburger in 1892 (84) discusses the formation of motile 
cells in algae and in ferns. At this time, Strasburger inclined 
toward a belief in the general occurrence of centrosomes in 
plants. In the much-elongated, spiral, motile cells of ferns he 
finds the nuclear matter in the thicker posterior coils and kino- 
plasm in the slender anterior coils from which the cilia grow. 
In the antherozoid of Marsilia, the spiral consists of eleven 
coils, ten of which are slender and nearly uniform in diameter. 
Prom the last of these ten coils arise the cilia. The eleventh 
coil is larger and in its hollow lies the vesicle. Strasburger be¬ 
lieves that in this case the nuclear material is to be found in 
the heavy posterior coil, that the kinetic center is at the anterior 
end and that the numerous intermediate coils consist of kino- 
plasm. 
Belajeff in 1894 (11) studied the development of anther o- 
zoids in Chara. He did not succeed in finding centrosomes in 
the nuclear divisions in the antheridial filaments. Within the 
antherozoid mother cell the nucleus assumes a lateral position. 
A deeply staining thread is seen in contact with the nucleus at 
one end and extending along the plasma-membrane for some 
distance. This thread Belajeff thinks may have been derived 
from an * c attraction-sphere. 5 ’ The cytoplasm on the opposite 
side of the nucleus pushes out into a slender curved horn—this 
is the posterior end of the antherozoid. The cytoplasm now 
shrinks in about the elongating anterior thread so that the 
thread comes to lie in a pointed projection on the cell surface. 
Prom this projection, two long cilia grow out. Purther de¬ 
velopment consists in the elongation of both the nucleus and the 
