1897 | ZAMIA AND GINKGO 227 
ently. The antherozoid which is utilized in fecundation swims 
into the protoplasm of the archegonium fora short distance, 
where it undergoes a remarkable change. In very numerous 
sections shortly after fecundation the spiral ciliiferous band of 
the antherozoid which, it will be remembered, is developed by 
the gradual extension of the membrane of the centrosome-like 
body, appears uniformly lying in the protoplasm at the apex of 
the archegonium. It shows very plainly and presents nearly 
the original form of the antherozoid ( fig. 3), but all traces of 
the nucleus and cytoplasm, which originally made up the main 
body of the antherozoid, have disappeared. The band, preserv- 
ing its original spiral form, now lies free in the protoplasm of 
the archegonium. No instance has been found of the occur- 
rence of more than one antherozoid presenting this appearance, 
and in every fecundated archegonium carefully examined one of 
these bands has been found. Since it was evident from this 
that the nucleus of this antherozoid must be the one utilized in 
fecundation, search was made for intermediate stages. Fortu- 
nately several have been found which support this view of the 
matter. In three different cases, immediately in the rear of the 
isolated spiral ciliiferous band described above, a nucleus has 
been found which, judging from its size and appearance, is 
evidently the nucleus of this antherozoid (figs. ¢ and 2). I 
have been unable to determine the fate of the cytoplasm which 
Surrounded the nucleus in the original antherozoid form, but 
from the slightly different density and constitution of the pro- 
toplasm which now lies between the spirals of the ciliferous 
band, it would seem that it simply unites with that of the 
archegonium. I have thus far been unable to find any other 
intermediate stages in the passage of the male nucleus, but it 
may be assumed from the above observations that shortly after 
the antherozoid enters the protoplasm of the archegonium, the 
nucleus escapes from the body of the antherozoid and from this 
point wanders alone to the oosphere. After fecundation the 
male nucleus appears as a small nearly round body in the upper ~ 
portion of the oosphere into which it has penetrated ( fig. 3): 
