This is equally true of the phenomena of apogamy and apospory in the light of recent researches into the effects of external conditions on reproduction.
Xlviii.; Farmer and Digby, Studies in Apospory and Apogamy in Ferns, Ann.
The phenomena of apogamy and apospory which have now been observed in a number of Ferns, may be mentioned here.
In apospory the converse phenomenon is seen, the gametophyte springing vegetatively from the sporangium, receptacle of the sorus, or leaf-margin of the fern-plant.
In a number of cases, though not in all, apospory appears to be correlated with a failure of the sporangia to develop.
A number of facts regarding the Algae, and also those relating to such deviations from the normal life cycle as apogamy or apospory, may be regarded as lending support to this view, which, in contrast to the theory of antithetic alternation, has been called that of homologous alternation.