PHAOPHYCE.E 65 
But the absence of cilia is not confined to this order. 
In the Fucacewe the oospheres are motionless. In the 
Tulopteridacece the homologous bodies are also motion- 
less, while in the Eetocarpacew, Hetocarpus pusillus pro- 
duces immobile spores in the plurilocular sporangia. 
This physiological condition may be misleading when 
made too much of in a morphological argument. If 
we disregard it, and take into account the character 
of the vegetative organs, the balance of evidence 
points to affinity with the Phwophycece. It may be 
objected that the trichothallic growth of Cutleria is 
very different from that of the Dictyotacew. But it 
may be recalled that the growth of the Aglaozonia 
or non-sexual forms of Cwtleria is not trichothallic, 
but by marginal initials. Again, it would be unwise 
to lay down a hard and fast rule in this matter when 
we remember the tuft of hairs at the apical dimple 
in young Fucus plants, for example, which may 
indicate, as other facts do, that no great gulf 
separates trichothallic growth from that by an apical 
cell or group of equivalent initial cells. The 
Dictyotacee are placed here next the Cutleriacee 
more from contrast than implied affinity. We may 
compare the three kinds of reproductive bodies, 
ciliated in the one case, unciliated in the other. 
Since such loss or absence of cilia occurs elsewhere 
in the Phwophycce, it appears to be more reasonable 
to regard the Dictyotacew as degenerate members of 
this group, with motionless reproductive organs 
occurring in definite sori for the most part as in 
Cutleriacew, though not in conceptacular fruits ag 
in Pucacec. 
F 
