BRIEFER ARTICLES 
ORIGIN OF THE THALLUS, ALTERNATION OF GENERA- 
TIONS, AND THE PHYLOGENY OF CUTLERIA.’ 
THe Cutleriacee (Cutleria and Zanardinia) may be considered 
among the most interesting and remarkable forms of the Phaeosporeae. 
The two fronds, sexual and asexual, of the single species of Zanar- 
dinia (Z. collaris) are identical. The genus Cutleria, represented in 
Europe by two species, has a sexual thallus whose structure and devel- 
opment is very different from the asexual form. The oogonia and 
antheridia are borne upon the plant named Cutleria, whose thallus is 
composed of and formed through the union of marginal filaments 
remaining free upon the periphery, and becoming divided by partitions 
with the thickening of the thallus following the fusion. So the thallus 
is both a pseudoparenchyma and a true parenchyma. 
The sporangia are borne in the upper surface of Aglaozonia, which 
has a creeping habit, and grows by marginal cell division like Zonaria. 
It now seems to be established that Ag/aozonta parvula is the asexual 
form of Cudleria multifida, and one may suppose with Falkenberg that 
A. chilosa is the asexual form of C. adspersa. In reality, however, this 
supposition rests upon the fact that we do not know in Europe any 
other species of Cutleria or Aglaozonia. 
But I have found at several points on the coast of the gulf of 
Gascony a new Aglaozonia, the Zonaria melanoidea of Schousboe, dis- 
covered at the beginning of the century at Maroc, and not reported 
since, whose Aglaozonia nature has remained unrecognized. For 
Various reasons I consider A glaozonia melanoidea to be the sporophyte 
of C. adspersa. If that form has not been seen up to the present in 
the Mediterranean where C. adspersa is not rare, it is without doubt 
because of its very great resemblance to Ralfsia. But since we do not 
know the gametophyte of A. chilosa, and as the Cutlerias are plants 
with a rather large thallus, conspicuous and easily recognized, it 1s 
SAUVAGEAU of his paper 
This contribution is in part a résumé by PROFESSOR 
» Ann. d. Sci. Nat., Bot. 
T 
entitled “Les Cutleriacee et leur Alternance de Générations, 
10: 265. 1899. ‘Translated by Dr. Bradley M. Davis. 
1900] 277 
