436 BOTANICAL GAZETTE [NOVEMBER 
were allowed to remain upon the original solution on which the spores 
had been sown. A luxuriant growth of algae developed in all of the 
cultures, which added to the unfavorable growing conditions. 
March 9g, 1917, in both series of cultures, apogamous embryos were 
observed on the prothallia which developed in Knop’s full solution from 
spores collected in Maine. Archegonia were developed on many of the 
heart-shaped prothallia, while in some of the cultures on the smaller 
prothallia antheridia were present. Some of the archegonia appeared 
aborted. In most cases the apogamous embryos developed in the 
manner which has previously been described. However, a few cases of 
peculiar development were observed. Miulticellular hairs or outgrowths 
formed at the base of the first leaf or leaves of the young sporophyte, or at 
various places on it. 
On one prothallium a long cylindrical outgrowth several cells in 
thickness developed from the cellular mass along with the leaves of 
the apogamous sporophyte. As growth proceeded, this outgrowth 
broadened out into a one-celled prothallium-like structure, after which 
it again assumed the cylindrical shape bearing tracheids; at its apex it 
tended to return to the prothallium structure. On another prothallium 
an outgrowth which had developed from the notch of the prothallium 
and projected as a narrow process broadened at the apex, forming a 
. Slightly notched prothallium. 
The only cases of apogamy on prothallia developed from spores 
collected at Ithaca, New York, occurred in the culture of Knop’s full 
solution which had been kept in the laboratory. Most of the apogamous 
embryos originated from cellular masses formed on the prothallia, but 
on one prothallium a cylindrical outgrowth bearing tracheids developed 
from the cells in the notch. At the apex of this long cylindrical process a 
cellular mass was formed, from which the leaves, root, and stem of the 
apogamous embryo developed. 
Two series of cultures of Osmunda cinnamomea and O. Claytoniana 
were made at the same time, in the same manner, and placed under the 
same conditions as the cultures of Phegopteris polypodioides. Apogamous 
embryos were observed March 9, 1917, on the prothallia in the following 
solutions: Prantl’s full solution, Prantl’s solution with NH,NO; omitted, 
and Prantl’s solution with MgSO, omitted. Some of the apogamous 
embryos developed from cellular masses; others originated as cylindrical 
outgrowths containing tracheids, from the notch of the prothallia, bear- 
ing at their apices cellular masses which gave rise to the leaves, root, 
and stem of the sporophyte. On one prothallium an apogamous sporo- 
phyte formed near the notch, while at its base a lobe of the prothallium 
