392 



But, however this may be, it is at any rate very interesting that this 

 intermediate form has now been found between the marine Rhodo- 

 chorton Rothii and the true air-alga, Rhodochorton islandicum. 



As mentioned above, Rhodochorton Rothii can grow far above 

 sea-level in piaces where it is not liable to be reached by the spray 

 for a long period, and liere in the Færoes it 

 is not only subject to dissiccation, but owing to 

 the rainy climate that prevails it is often soaked 

 through by rain water, which explains its oc- 

 currence in waterfalls near extreme high-water 

 mark, so extreme that it can only be overflowed 

 by the sea during very high water. Thus I 

 found it south of Thorshavn, on the east side 

 of Stromo, near Gliversnæs, where a small 

 stream dashed perpendicularly down over the 

 edge of a rock, and just where the jet of water 

 fell on the subjacent rock, there Rhodochorton 

 Rothii grew luxuriantly in dense, reddish-purple 

 tufts, and Jonsson found it growing in similar 

 localities near Klaksvig. The specimens found 

 in waterfalls seem to correspond exactly to 

 Rhodochorton intermedium Kjellm. 1 They had 

 — what Kjell man points out as characteristic 

 of the latter — their main filament irregularly 

 branched along their whole length and further 

 scattered lateral branchlets bearing tetraspores 

 (see fig. 61), while the branches of typical Rho- 

 dochorton Rothii spring from a limited space 

 on the main branch as is figured beautifully by 

 le Jolis (Alg. Mar. Cherb., pi. V). This clustering 

 together of the long branches in typical Rho- 

 dochorton Rothii is often occasioned by the 

 growing out of the tetraspore-bearing branchlets 

 into numerous long branches after the tetrasporangia have fallen 

 off (see fig. 62). I have often found this to be the case wilh 

 the Færdese specimens. The above -mentioned specimens from 

 the water-fall resemble Kjellman 's not only in their different 

 branch-system , bul also in their ereel filaments being of the same 



1 Kjellman, F. R.: Om Spetsbergens marina, klorofyllforande Thallophyter. 

 I, p. 28. (Bihang t K. Svenska Vet.-Akad. Handl 13. 3, Nr. 7, 1875). 



Fig. 61. Iihodochorlon Rothii 

 (Turt.) Niig. Portion of fila- 

 ment with lateral branchlets 

 bearing tetraspores. 65: 1. 



