1000 REPORT—1896. 
my preliminary notice, in which the prothallus will sprout forth directly from the 
ond.’ 
‘ It is unnecessary to remind English botanists that Pringsheim’s hypothetical 
aposporous ferns are now perfectly well known in the flesh; such cases having 
been first observed by Mr. Druery and then fully investigated by Professor 
Bower. 
A very remarkable case of direct origin of the odphyte from the sporophyte has 
lately been described by Mr. E. J. Lowe, in a variety of Scolopendrium vulyare. 
Here the young fern-plant produced prothalli bearing archegonia as direct out- 
growths from its second or third frond. The specimen had a remarkable history, 
for the young plants were produced from portions of a prothallus which had been 
kept alive and repeatedly subdivided during a period of no less than eight years. 
I cannot go into the interesting details here, they will be published elsewhere ; 
but I wish to call attention to the fact that in this case the production of the sexual 
from the asexual generation, occurring so early in life, has no obvious relation to 
suppressed spore-formation, and so appears to differ essentially from the cases first 
described, which occurred on mature plants. I believe Mr. Lowe’s case is not an 
altogether isolated one. 
The converse phenomenon—that of apogamy—or the direct origin of an asexual 
plant from the prothallus without the intervention of sexual organs, has now been 
observed in a considerable number of ferns, the examples already known belonging 
to no less than four distinct families: Polypodiacez, Parkeriaceze, Osmundacez, 
and Hymenophyllacee. In Trichomanes alatum Professor Bower found that 
apospory and apogamy co-exist in the same plant, the sporophyte directly giving 
rise to a prothallus, which again directly grows out into a sporophyte ; the life- 
cycle is thus completed without the aid either of spores or of sexual organs. Dr. 
W. H. Lang who has recently made many interesting observations on apogamy, 
will, I am glad to say, read a paper on the subject before this section, so I need say 
no more. 
Imust, however, express my own conviction that the facility with which, inferns, 
the one generation may pass over into the other by vegetative growth, and that in 
both directions, is a most significant fact. It shows that there is no such hard and 
fast distinction between the generations as the antithetic theory would appear to 
demand, and in my opinion weighs heavily on the side of the homology of sporo- 
phyteand odphyte. I cannot but think that the phenomena deserve greater attention 
from this point of view than they have yet received. 
A mode of growth which affords a perfectly efficient means of abundant propa- 
gation cannot, I think, be dismissed as merely teratological. 
Since the foregoing paragraph was first written Dr. Lang has made the remark- 
able discovery (already communicated to the Royal Society) that in a Lustrea 
sporangia of normal structure are produced on the prothallus itself, side by side 
with normal archegonia and antheridia. I cannot forbear mentioning this striking 
observation, of which we shall hear an account from the discoverer himself. 
The strongest advocate of the homology of the prothallus with the fern plant 
could scarcely have ventured to anticipate such a discovery. 
RELATION BETWEEN MossEs AND FERNS. 
Goebel said, in 1882: ‘The gap between the Bryophyta and the Pteridophyta is 
the deepest known to us in the vegetable kingdom, We must seek the starting- 
point of the Pteridophyta elsewhere than among the Muscinez : among forms which 
may have been similar to liverworts, but in which the asexual generations entered 
from the first on a different course of development.’! I cannot help feeling that 
all the work which has been done since goes to confirm this wise conclusion. 
Attempts have been made in the most sportsmanlike manner (to adopt a phrase of 
Professor Bower's) to effect a passage over the gulf, but the gulf is still unbridged. 
I cannot see anywhere the slightest indication of anything like an intermediate 
form between the spore-bearing plant of the Pteridophyta and the spore-bearing 
1 Schenk’s Handbuch der Botanik, vol. ii. p. 401. 
