56 BOTANICAL GAZETTE (JULY 
may be an x structure, and the spores may have been formed in the 
usual way, so that the new gametophyte will have only $x chromo- 
somes; an interesting surmise in view of the fact that nearly related 
forms are known to show 12, 24, and 48 chromosomes. Or there 
may have been a doubling of the number and a subsequent reduc- 
tion at the formation of spores. The appearance of a sporangium 
upon a prothallium will be accepted as a case of apogamy. 
Discussion 
LANG (2), in his work on apogamy, grew prothallia from spores. 
Such prothallia, when kept dry, in direct sunlight, and watered only 
from below, developed leaves, roots, and ramenta on the prothallia 
themselves or on. the cylindrical processes. The process continued 
as a leaf, or it produced sporangia, and tracheids were found both 
in the process and in other parts of the prothallium. When sporangia 
were found on a cylindrical process, tracheids were always present 
‘in the underlying tissue. YAMANOUCHI (7) reports very slow growth 
and few abortive archegonia in his material kept in bright light 
and dry air. 
My material was not in bright light and was given plenty of } 
moisture, being kept in as nearly normal condition as possible, 
except for the entire absence of liquid water. Consequently, if 
this is apogamy, the lack of fertilization is apparently the only factor 
involved in its appearance here, for in this material archegonia were 
very numerous and were normal in every respect, and fertilization 
did take place when water was supplied. In this respect it seems to ~ 
be like Marsilea, where SHAw (3) and STRASBURGER (5) found that — 
if megaspores of Marsilea Drummondii were isolated, and therefore : 
fertilization prevented, parthenogenetic (apogamous) embryos were — 
produced. 
The gametophyte number of chromosomes is approximately 16. — 
This number is very suggestive of Osmundaceae (SMITH 4, STRAS- | 
BURGER 6, YAMANOUCHI 8), which is reported to have 16 chromo- 
somes in the spore mother cell. However, the young sporophyte — 
does not resemble the mature form of Osmunda, and whether it~ 
resembles the sporeling I cannot tell, not being familiar with the — 
sporelings of Osmunda. 
