60 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1. 



Fig. 63. Acrochætium ernothrix nov. 



spec. Erect ramified filament with 



sporangia-bearing branchlets ended 



with hairs. (About 150:1). 



As to the base I much regret 

 that I have not been able to 

 state with certainty how it is 

 formed having only had a single 

 specimen. By means of chlor- 

 zinc jodine, which coloured the 

 Acrochætium and at the same 

 time had a clearing influence 

 upon the tissue of the host 

 plant, I have arrived at the 

 conclusion that the base most 

 probably consists of a few 

 creeping filaments somewhat 

 immersed in the tissue of the 

 host plant. 



From this basal part an 

 erect filament arises which im- 

 mediately begins to give off bran- 

 ches forming in this way a small 

 tuft about 400// high. The prin- 

 cipal filaments are rather straight 

 (Fig. 63) ; they branch out in all 

 directions along their whole 

 length but mostly in the upper 

 part. They consist of cells about 



5 — 6// broad and 15 — 18// long. 



The chromatophore (Fig.64) is band- 

 shaped often with more or less long 

 prolongations along the wall of the cell; 

 in the middle a large pyrenoid is pre- 

 sent. 



The branches are of two kinds, short 

 sporangia-bearing branchlets (Fig. 64) 

 and ordinary branches growing out to 

 filaments like the principal filaments 

 and again branched in the same way. 



The branchlets have a very cha- 

 racteristic appearance (Fig. 64). They 

 consist of two or three, rarely more, 

 cells the uppermost of which taper 

 greatly and runs out in a long hair-like 

 prolongation composed of two or three, 



Fig. 64. Acrochætium erno- 

 thrix nov. spec. Branchlet 

 with sporangia and hair. 

 (About 350 : 1). 



