18 Wisconsin Academy of Sciences, Arts, and Letters. 
a. The shape of the last coil and a half is almost the same 
as in the two-coil stage (figure 20). The anterior part forms 
an additional turn of comparatively small diameter. 
Nothing remains visible of the structure of the nuclear con¬ 
tents. With the increasing homogeneity of the nucleus, the 
blepharoplast becomes more difficult to distinguish. In figure 
twenty-two, there is no line of demarcation between the portion 
of the spiral composed of blepharoplast alone, i. e. the beak, 
and that which also contains the nucleus. The two portions 
form a smooth curve and the stain is uniform, red or gray, 
according to whether the triple stain or the iron-haematoxylin 
is used. In the triple stain, however, when the preparation has 
been deeply stained in the blue, the blepharoplast can still be 
discerned as a purple line bordering the red of the nucleus (fig¬ 
ure 23). 
The changes in the cytoplasm are not marked. The bulk of 
it lies as before in the hollow of the large posterior coil. Its 
form can be seen in figure twenty-one b which represents twenty- 
one a with the last half turn removed. A coil near the anterior 
end (figure 22) shows the cytoplasm drawing in about the nu¬ 
cleus. The cytoplasm forms a spiral following that of the 
nucleus, very bulky in the hollow of the large posterior coil but 
growing more and more slender toward the anterior end. The 
posterior end of this spiral has the same shape in ripe anthero- 
zoids so long as they are still in the sac. 
The origin of the cilia is not clear in my preparation. As 
the mature antherozoids become active the cilia are seen as a 
coil of threads about the anterior end (figure 24). They are 
fastened to the coil along the tip, curve outwards, then run back 
in a spiral following the nucleus. In figure 25 a portion of the 
cilia are shown free throughout their length and are directed 
forward, still loosely coiled. 
The development of the antherozoid in Aspidium falcatum is 
essentially similar to that of Adiantum. As will be described 
below, the antherozoids of this species never function, since the 
sporophyte of Aspidium falcatum is always formed apoga- 
