292 BOTANICAL GAZETTE [ APRIL 
Several years ago, in his brilliant monograph on the evolu- 
tion of the sporangium, Bower (14) suggested that emergences 
erupted from an indefinite concrete imbedded mass of sporogen- 
ous cells, and by progressive sterilization and branching resulted 
in discrete sporangia. In support of his view, he marshaled 
existent bryophyte and pteridophyte forms that he regards as 
analogous to those that may have appeared in the direct line 
of evolution. The same kind of argument may be applied to 
the origin of the sex organs. I have no idea that any of the 
brown or red algae represent lineal ancestors of the liverworts 
or ferns as we now know them; but if the Phaeophyceae are 
perchance an offshoot from green algae, the method in which 
they produce their reproductive cells may be like that of their 
forbears, from whom also the archegoniates have .probably 
evolved. It is possible that the investigations of apogamy now 
proceeding will throw some new light on the subject. I hazard 
the suggestion that the origin of the apogamous sporophyte is 
among latent gametogenous cells of the thallus, which under 
unknown conditions develop sporangia without the formation of 
sex organs. Such a hypothesis may seem rash, but there is, I 
think, no inherent improbability in the theory, while it furnishes 
a suggestive line for investigation among the brown algae, which 
is a sufficient reason for its being. If Farmer’s (15) preliminary 
announcement of the fusion of the nuclei of neighboring cells of 
fern prothalli, as a step preliminary to the formation of the 
apogamous sporophyte, is confirmed, are these fusing cells to be 
regarded as stable vegetative cells, or as potential isogamous 
gametes? If the latter, is it not conceivable that they are sur- 
viving cells of a former fertile region which normally are sterile, 
but on occasion may regain potentiality?’ 
THE UNIVERSITY OF CHICAGO, 
LITERATURE CITED. 
1. Davis, B, M., Origin of the archegonium. Annals of Botany 17: 477- 
492. 1903. 
2. Hy, F., Recherches sur l’archégone et : Cole saree du fruit des 
~ Muscinées. ‘Ann, Sci. Nat. Bot. VI. 121. 188 
