482 Davis . — The Origin of the Archegonium . 
development. Gotz 1 believes them to stand for the walls of 
a reduced archegonium, thus removing this sexual organ of 
the Charales from the category of the gametocyst and regard- 
ing it as a degenerate archegonium plus the enveloping whorl 
of filaments that surrounds the egg and forms the crown. 
Gotz calls the Charales Phycobryophytes, and does not con- 
sider them to be directly connected with the Algae. This is 
a very interesting suggestion, although objections present 
themselves in the complexity of the processes required to 
bring about the degeneration of such a well-established organ 
as the archegonium and its displacement by an equally 
elaborate envelope of filaments. It seems to the writer that 
the accessory cells (Wendungszellen) may be nothing more 
than the final and somewhat irregular expression of the vege- 
tative activities of a growing point that is about to become 
transformed into a sexual organ. In any event all botanists 
will probably agree with Gotz and others that the female 
sexual organ of the Charales is not a primitive archegonium. 
There seems to be, then, no sexual organ of the hetero- 
gamous Algae from which the gametangium (multicellular) of 
the Bryophytes could have arisen. We are forced to seek for 
clues in other groups and among other structures than these 
gametocysts (unicellular). 
The structure of the archegonium and antheridium would 
suggest a derivation from some multicellular organ, a sporan- 
gium or gametangium. But unfortunately few structures of 
this character are known among the Chlorophyceae, that 
group of Thallophytes which naturally is considered nearest 
to the Bryophytes. We should be forced to assume a more 
extensive existence of such multicellular structures in groups, 
now extinct, which were much nearer the main line of ascent 
to the Bryophytes than any surviving Algae. 
To what extent would we be justified in placing all the 
heterogamous green Algae far away from such a main line, 
and in recognizing a region of extinct groups with sexual 
1 Gotz, Ueber die Entwickelung der Eiknospe bei den Characeen. Bot. Zeit. 
lvii, 1, 1899. 
