90 Church.— The Polymorphy of 
A further exaggeration of the basal segmentation resulted 
in the formation of a small irregular attachment disc (Fig. io); 
but the latter exhibited no immediate tendency to extend 
into dorsiventral lobes, the main energy of growth being, in 
this embryo, clearly localized . in the filamentous portion. 
This continued to grow, throwing out branches above and 
rhizoid attachment-hairs below. In the case of plants 
growing on the sides of the vessel, the filaments showed 
a tendency to attach again at any point in their length, 
sending out rhizoids, and initiating a new intercalary zone 
of growth above each such attachment : but it is possible 
that this may be an abnormal result of cultivation, as the 
same tendency can be observed in cultures of old Cutleria 
plants, where the reproductive filaments elongate and attach 
themselves to the sides of the vessel by rhizoids and bear 
gametangia at irregular intervals ; the filamentous portions 
of the adult Cutleria are, in fact, still in the condition of 
these filamentous embryos. 
It will be seen that even these young plants present the 
majority of the essential characters of the Cutleria - thallus : 
there is, for example, the same intercalary growth of a 
filamentous apex, with irregular segmentation behind the 
growing-point leading to a multicellular condition, and the 
same throwing-out of branches of similar growth and of 
attachment-rhizoids to supplement the primitive holdfast. 
The only point lacking is the aggregation and fusion of the 
branches behind the growing-points to the peculiar fasciated 
thallus of the adult Cutleria. 
At the beginning of May, a culture of these young plants, 
now a month old and forming tufts of actively assimilating 
filaments, was taken to Oxford and kept under observation 
in a shaded situation in a south window of the Botanical 
Laboratory. The plants continued to live and assimilate 
vigorously, forming a bright brown woolly growth of Ecto- 
carpus - like filaments in the unchanged water, and maintaining 
their position at the surface in virtue of the gas-bubbles 
evolved. In still water, this phenomenon affords the surest 
