240 BOTANICAL GAZETTE [APRIL 
Goebel (1) states his approval of Hegelmaier’s view, but the 
occasional periclinal division of the external cells does not 
escape his notice, though he considers it as merely adding to 
the thickness of the wall. Bower (5), on the other hand, 
observed both the superficial origin of the sporangium and the 
failure of the first periclinal divisions to completely delimit the 
archesporium. 
As already stated, I do not find the outer wall separate 
from the sporogenous complex from the beginning. On the 
contrary, it is distinctly active in increasing the dimensions 
of the sporangium. Ultimately the superficial layer loses 
some of its protoplasmic contents, and assumes the appearance 
of an epidermis. It sometimes happens that this separation of a 
wall layer occurs quite early (fig. 47), but oftener it is not till 
the sporangium has come to consist of many hundred cells. 
Even then periclinal divisions do not entirely cease. 
According to my observations there is no regularity in the 
arrangement of the cells within the sporangium. The discovery 
of this was a great surprise to me, for Goebel’s statement is very 
explicit: ‘‘Each of the cells composing the archesporium has 
an independent growth,” and in this he has been corroborated 
by Sadebeck and Farmer. Bower has not traced the history 
of the sporangium with any fullness; he merely states that his 
results are confirmatory of Goebel’s and his figures certainly 
convey the impression that each cell of the archesporium has an 
independent growth. But he has made use of the same style of 
drawing in representing the sporangia of other genera (Lycopo- 
dium, Selaginella, Equisetum), in which no such claim is made. 
In view of my own observations and of Bower’s drawings, it is 
difficult to know just how much is meant by the phrase “inde- 
pendent growth.” 
In the case of bryophyte antheridia the primary spermatog- 
enous cells are clearly distinguishable throughout the whole 
development of the antheridium, although each may become 
divided up into a hundred or more sperm mother cells. The 
individuality of the original cells is marked in several ways:. 
