OctToBER 8, 1897. ] 
the experiments performed by Goebel on 
the ostrich fern. The results he reached 
were the same; the sporophyll was more or 
less completely transformed to a foliage leaf. 
Goebel regards this as the result of the cor- 
relation processes, and looks upon it as in- 
dicating that the sporophyll is a transformed 
foliage leaf, and that the experiment proves 
the reality here of the modification which 
was suggested in the theory of metamorpho- 
sis, and thus the foliage leaf is ]Jooked upon 
by him as the primary form. Another inter- 
pretation has been given to these results, 
viz., that they strengthen the view that the 
sporophyll, from a phylogenetic standpoint, 
is primary, while the foliage leaf is sec- 
ondary. What one interprets as a reversion 
another regards as indicating a mode of 
progress in the sterilization of potentially 
sporogenous tissue and its conversion into 
assimilatory tissue. It is, perhaps, rather to 
be explained by the adaptive equipoise of 
the correlative processes existing between 
the vegetative and fruiting portions of the 
plant, which is inherited from earlier times. 
Rather when spore production appears on 
the sporophyte could this process be looked 
upon as a reversion to the primary office of 
the sporophyte, so that in spore production 
of the higher plants we may have a con- 
stantly recurring reversion to a process 
which in the remote past was the sole func- 
tion of this phase of the plant. In this way 
might be explained those cases where spo- 
rangia occur on the normal foliage leaf of 
Botrychium, and some peculiar cases which 
Ihave observedin Osmundacinnamomea. In 
some of the examples of this species it would 
appear that growth of the leaf was marked 
by three different periods even after the 
fundament was outlined, the first a vegeta- 
tive, second a spore-producing, and third 
a vegetative again ; for the basal portions 
of the leaf are expanded, the middle por- 
tions spore-bearing, the passage into the 
middle portions being gradual, so that many 
SCIENCE. 
54T 
sporangia are on the margins of quite well- 
developed pinne. These gradations of the 
basal part of the leaf, and their relation to 
the expanded vegetative basal portion, 
showing that the transition here has been 
from partially formed foliage leaf to sporo- 
phyll after the fundament was established, 
and later the increments of the vegetative 
part from the middle toward the terminal 
portion, as shown by the more and more ex- 
panded condition of the lamina and de- 
creasing sporangia, indicate that vegeta- 
tive forces are again in the ascend- 
ency. This suggests how unstable is the 
poise between the vegetative leaf and sporo- 
phyll in structure and function in the case 
of this species. 
For two successive years I have endeav- 
ored by experiment to produce this trans- 
formation in Osmunda cinnamomea, but 
thus far without sufficiently marked results. 
The stem of the plant is stout, and this, to- 
gether with the bases of the leaves closely 
overlapping, contains considerable amounts 
of stored nutriment, which make it difficult 
to produce the results by simply cutting off 
the foliage leaves. The fact that these 
transformations are known to occur where 
fire has overspread the ground, and,as I 
have observed, where the logging in the 
woods seriously injured the stools of the 
plant, it would seem that deeper seated in- 
juries than the mere removal of foliage 
leaves would be required to produce the 
transformation in this species. It may be 
that such injury as results from fire or the 
severe crushing of the stools of the plant 
would be sufficient to disturb the equilib- 
rium which existed at the time, that the 
action of the correlative forces is changed 
thereby, and there would be a tendency for 
the partially developed foliage leaves to 
form sporangia, then when growth has pro- 
ceeded for a time this balance is again 
changed. 
The theory that the foliage leaves of the 
