6 Campbell. — Observations on the Development 
stages, the' body becomes quite homogeneous. In the nearly 
full-grown spermatozoid, the body is much narrower and 
tapers to a fine point at the forward end (Fig. 12). From 
a careful study of all stages, it seems certain that only a very 
small part of the forward end is of cytoplasmic origin. 
Unfortunately, I was unable to get any free spermatozoids, 
so that it was impossible to test them with Strasburger’s 1 and 
Belajeff’s 2 methods, but in the full-grown spermatozoid 
within the antheridium the nuclear origin of all but the 
extreme forward end was unmistakable. Perhaps, as Stras- 
burger claims, the cilia-bearing part is cytoplasmic and 
the cilia are direct outgrowths of this part, but this point was 
not satisfactorily proven. The origin of the antheridium, as 
well as its development and its complete immersion in the 
prothallium, have their nearest approach in Eqtdsetum. The 
species of Lycopodium investigated by Treub 3 also show 
a good deal of resemblance. Among the ferns, from what is 
known, the Ophioglosseae show a close resemblance, but the 
development of the antheridium is too imperfectly known to 
allow of a satisfactory comparison. The antheridium of 
Osmunda is in some degree intermediate between that of 
Marattiaceae and the more specialized Leptosporangiatae. 
The Archegonium. 
The archegonia seem to be confined to the lower side of 
the midrib, and are formed some distance behind the growing- 
point of the prothallium. So far as could be determined, any 
superficial cell of the apical meristem can develop into an 
archegonium. The succession of divisions seem to correspond 
exactly with those of the other ferns. The mother-cell divides 
usually into three superimposed cells (Fig. 13), of which the 
lowest, b , usually divides several times by vertical walls and 
forms the base of the archegonium. From the central one, 
by transverse divisions are formed the canal-cells and egg, 
1 Loc. cit. p. 106. 
2 Belajeff, Ber. der Deutschen Bot. Gesellschaft, Dec. 1889. 
3 Annals of the Botanical Garden, Buitenzorg, Vols. iv, v, vii. 
