69 



mentioned clamps where a wall is present. Kuckuck who has 

 examined a dried specimen collected by the late M"" Vickers 

 at Barbadoes has also found them. He writes I. c. p. 181 : »Da- 

 gegen zeigten die Sprossenden im unteren Telle des Btischels 

 Gruppen von locker stehenden Rhizinen, die aus der oberen 

 stumpfen Kuppe des Sprosses zwischen und neben den Tochter- 

 sprossen abzweigen«, I think that these organs may also serve 

 to strengthen the plant, just as these and the clamps can help 

 to attach loose fragments of the plant to the bottom again. 



The cell-wall in the older part of the thallus is rather thick, 

 thinner in the younger; it is nicely striated in an irregularly un- 

 dulating way. The cell- 

 plasma contains numerous 

 plate-shaped small chrom- 

 atophores of irregular pol- 

 ygonal outline with the 

 corners running out into 

 shorter or longer, thin 

 prolongations connected in 

 a reticular way (Fig. 53 d). 

 In the middle of the 

 chromatophore a rather 

 large pyrenoid is present. 

 Underneath the chrom- 

 atophores we find the 

 numerous nuclei in regular 

 arrangement. 



As in so many related 

 species the contents of the 

 cell are often found con- 

 tracted to some larger and 

 smaller balls richly filled 

 with chromatophores and nuclei etc. ; we find them figured by 

 KtTTziNG, »Tab. phycol.«, vol. VI, tab. 88. How far these balls 

 becoming free are able to produce new plants 1 cannot tell, but 

 it is very likely. 



Fructiferous cells occurred rather often in my collections. 

 The whole cell is transformed into a sporangium (Fig. 54 a) 

 and the zoospores escape through numerous holes formed in 

 the cell wall in exactly the same way as found in Siphono- 

 cladus tropicus. Quite in accordance with this species the holes 

 protrude a little and have radiating striations. Also the cell 



Fig. 54. Ernodesmis verticillata (Kiitz.) Borgs. 

 a, the upper end of a branch transformed 

 to zoosporangium (25:1). b, a single clamp 

 (20:1). c, the top of a branch with small 

 branches, one of these with a rhizoid-like 

 appendix, in the middle the annular cica- 

 trix from a branch torn of (8:1). d, branch 

 with a rhizoid-like appendix (8:1). 



