684 Lewis.— The Life History of Griffithsia Borne liana. 
tetraspores were found together with antheridia or procarps, but in no case 
were tetraspores and cystocarps found on the same plant. Cytological 
investigation of Spermothamnion is much to be desired. 
The theory of homologous alternation in the red algae outlined above 
is almost identical with the view of Pringsheim as to the relations within 
this group (64). He states (p. 897), ‘die Annahme ist nachstliegend, dass 
bei Florideen und Dictyoteen zwischen Exemplaren mit Kapselfriichten 
und Exemplaren mit Vierlingsfriichten eine Abwechselung besteht.’ 
Pringsheim’s view was based, however, on a very different kind of evidence 
from that brought forward in the present paper. 
The evidence at hand seems to justify the following conclusions: 
1. There is in Griffithsia an antithetic alternation of generations, the 
gametophyte being represented by the sexual plants, the sporophyte by the 
sporogenous cells of the cystocarp. 
2. In addition to this, there is a regular succession of tetrasporic 
individuals and sexual individuals. The tetrasporic individuals resemble 
the sporophyte in number of chromosomes ; they resemble the gametophyte 
in morphological differentiation. They are to be considered as a phase 
of an homologous alternation of generations, not the equivalent, wholly 
or in part, of the sporophyte of Archegoniates. 
Randolph-Macon College, 
Ashland, Virginia. 
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