THE CCENOCYTIC INDIVIDUAL 61 



chlorophyll in it, the mould hypha differs in two important 

 respects from the Spirogyra filament ; in the first place, it 

 is not a single-cell series, and in the second, lateral branching 

 takes the place of intercalation. The hypha of the mould 

 mycelium is not composed of separate cells shut off from 

 each other by walls, but has a long tubular structure con- 

 taining multinucleate contents, and divided or not divided 

 at intervals by transverse septa. Each such non-septate 

 mycelium, or segment of septate mycelium, is what is termed 

 a ccenocyte. This, however, is not to be regarded as a species 

 of long multinucleate cell. 



When we talk of the " cells " of Spirogyra we really 

 refer to the separate nucleated protoplasmic entities or 



* ESI 



3- mc^r^scr 





Fig. 10. — Showing that ccenocytic is higher than filamentous 

 Continuity, a, diagram of a protoplast enclosed by walls, 

 the whole being termed a " cell " ; B, part of a cell-series or 

 filament of Spirogyra, presenting Serial Continuity ; c, 

 ccenocyte of septate mycelium : in one respect a serial multiple 

 of any cell of b, but containing as it does two parallel series 

 of protoplasts, it presents us with the multiplication of b's 

 serial into Lateral Continuity. 



" protoplasts," plus their containing walls, which compose 

 the filament ; but the walls are only containers, they are 

 not essential parts of the entities, and the Spirogyra filament 

 is simply a long succession of protoplasts separated from 

 each other by partitions, whereas in mycelial growth there 

 is an increase of Continuity which shows itself in two ways ; 

 for between the septa or partitions of a ccenocyte there are 

 many protoplasts in series as compared to one protoplast 

 in the case of Spirogyra, and there is also the lateral con- 

 tinuity of parallel protoplastic series running along the 

 hypha (Fig. 10). 



The ccenocyte, in fact, might be looked on as the simplest 

 of all forms of " tissue," were it not that we restrict this 



