N U M B E R 4 (J . 19 













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1 EHT= 10.00 kV WD= 13 mm 

 MAG= SOX 1 Probe = 9 





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EHT= 10.00 kV WD= 12 mm 200tJm 

 MAG= SOX I Probe = 90 pA I 



DaM :17 Apr 2012 Tima ;13;35:1£ 

 Ouipui To - Defaurt Prinlei 

 CyclB Tims - 1S.G Sea 



FIGURE 13. CLuhniniorphiin! iicivostmtmu conceptacles in SHM images. Note that recalcified sporangium cell wails tend to be vertical 

 in asexual conceptacles (A; reflecting vertical orientation of sporangia), whereas cystocarpic conceptacles (B) appear as small angular 

 circles of various sizes (left arrow in B; cells of gonimoblast filaments |upper arrow] produce cystocarpic sporangia laterally). (A) Yearly 

 layers of buried bi- or tetrasporangial conceptacles (sporangial walls recalcified after burial; arrows). (B) Mature female (cystocarpic) 

 conceptacles. Midsections show a dumbbell shape (bottom right arrow) because of dissolution of the surrounding carbonate by periph- 

 erally developed spores. (C) Small, ovoid, male conceptacles with recalcified spermatangial mother cell walls (arrow). 



a dissecting microscope view of a vertical fracture or polished 

 slice, may superficially appear to be without structure. However, 

 at higher magnification, it is seen to be a rich mosaic, deriving 

 from the genetic control of cellular and tissue development as 

 influenced by the physical and biological environment. Mea- 

 surements of cell dimensions in SEM images demonstrate this 

 genetic-physical interaction. As shown in Eigures 14A, 14B, and 

 15, cell dimensions change seasonally. Cells within each filament 

 are linked by pore plates (pit connections and pit plugs in most 

 red algae), and the length, pore plate to pore plate, varies more 

 or less consistently from about 8 to 15 pm for both species; the 

 cell lumen diameter likewise ranges from 2 to 6 pm. There is a 

 strong tendency for cells to be shorter and wider in the winter 

 and early spring, with a lengthening and narrowing of the lumen 



in the summer and early fall (Figures I4A, 14B, 15). This pattern 

 is strongly apparent in most C. nereostmtiitn specimens from the 

 Aleutian Islands but less so in C. coinpcictiuu specimens from the 

 northwestern North Atlantic. 



Since tt)tal filament diameter, including the calcified cell 

 walls, is fixed at roughly 10-11 pm in C. iiereostratiim and 

 9-10 pm in C. coiupactiDu (except when filament branching 

 and tissue expansion is occurring), it is the total calcified cell 

 wall thickness that changes seasonally (Figure 16A,B). As can be 

 seen clearly in Figures 16 and 17, there is a well-defined inner 

 wall, with small, prismatic, radially oriented calcite crystals that 

 maintain about the same length (1 pm) and character through- 

 out their distribution and annual cycle. This wall type has 

 been described for most corallines for the last several decades 



