66 ON PROTOPLASMIC CONTINUITY IN THE FLORIDER. 
the cells at the joints, and forms a series of cellular rings, each 
of which bears a short stout spine. The cortex does not present 
so obvious a case of continuity as does that of Polysiphonia, but its 
the cortical cells by protoplasmic threads. The connections of the 
cortical célls inter se are most remarkable, being effected not by 
single threads, but by several, ae radiate from the central mass 
like the pseudopodia of a Bhizo d. Each thread carries a collar 
which resembles that met with A > Palgtishoute eee | and like 
it, appears, in some cases, to enclose a delicate diaphragm 
4. Primota. 
The genus Ptilota, so much admired for the loveliness of its 
forms, is no less remarkable for the striking examples it offers 
of protoplasmic continuity. Of eo be Floridee examined few 
have presented the phenomena i complete and demonstra- 
tive manner than the Ptilotas, airecalty, P. elegans. Wuhdatadtalls 
monosiphonous, like most of the plants previously considered, the 
_ older parts of this species become densely corticated. _The cent tral 
nothing but simple filaments composed of. quadrate or oblong cells. 
The protoplasmic bodies of these cells are in uninterrupted con- 
he 
w of the e protoplasmic bodies of the central cells of an older 
sha with their connections inter . and with the lateral ee 
At fig. 11 is a section of a still older part of the stipes, showing that 
