273 
Skawr — The Fertilization of Onoclea. 
drawn out on entering the slime. With all the stains used 
the darkest part of the body is a corkscrew-shaped homo- 
geneous rod, oval in cross-section, which tapers gradually 
forward and abruptly backward. It does not terminate in 
a sharp point at either end. In all the specimens which were 
noted closely the spiral turns of the body are in the direction 
of a left-hand screw. Webber 1 finds that the helicoid ciliated 
band in the spermatozoid of Zamia is coiled in the same 
direction. The number of turns varies with the length to 
which the corkscrew is extended : when shortened, like a 
watch-spring, it makes two turns (Fig. io b ) ; just outside the 
archegonium it usually makes about three and a half turns 
(Fig. 5) ; in the canal, when it becomes most extended, it 
may make five turns (Fig. 1). In all the forms an almost 
stainless band can be seen attached to the forward edge 
of the corkscrew, and extending beyond its forward point. 
This band is broadest toward the forward end, and it tapers 
backward to the thickest part of the corkscrew rod. The 
outer edge of the band appears to be thicker than the rest, 
and the thickening is greatest near the forward end. The 
dark rod is assumed to be the nucleus, and the wing-like band 
the cytoplasmic portion of the spermatozoid. The cilia did 
not usually stain enough to be visible ; but when Heiden- 
hain’s iron-haematoxylin was left rather dark they could 
be seen distinctly enough to show that some extended 
forward and others backward. They could not be traced 
to their respective points of attachment, and so they were 
omitted from the drawing (Fig. 8) which was made from such 
a specimen. No centrosome was seen. 
The nucleus of the spermatozoid has the same form as 
that figured by Campbell 2 for the developing spermatozoid 
of O. Struthiopteris . It extends through the greater part of 
the length of the body. In this respect it differs from the 
nucleus which Strasburger 3 found in the spermatozoid of 
Phegopteris . In the latter it occupied only the larger pos- 
1 Webber ’97, p. 17. 2 Campbell ’95, p. 131. 
3 Strasburger ’92, p. 116. 
