— 191 — 



Alhertisii Piccone collected at the Canary Islands and described by 

 Plccone. ') 



Piccone's paper was not available here in Copenhagen but 

 Professor No rdstedt has lent me a copy belonging to the Botanical 

 Institution in Lund and after seeing the figure of the general 

 appearance of the plant given by Piccone, it was also clear to 

 me that Piccone's plant is most probably the same as mine, but 

 on the other hand the description and detailed figures of Piccone 

 are so incomplete that nothing definite can be said of them. 



To be clear of all doubt I have therefore addressed myself to 

 Dr. Achille Forti in Verona, in whose possession Herb. Piccone 

 now is and he has allowed me to see the original specimen. 



From this and also from a microscopical examination of a 

 small piece 1 feel quite convinced that Piccone's plant must be 

 identical with the American, Of course, in the outer habit there 

 was a little difference: the specimen of Piccone being somewhat 

 more loosely ramified, as the joints were somewhat longer than 

 in the Bermudan specimens, which are more compact with shorter 

 joints and much denser ramification, while again the West Indian 

 specimens seem to reach somewhat larger dimensions with larger 

 joints. But upon these differences I do not think we can lay much 

 importance, as they can all very well be referred to the influence 

 of outer factors. Thus, the plant from the Bermuda Isles, according 

 to what Professor Farlow has recently communicated to me, was 

 growing "on corallinaceous rocks in grottoes", and my plant was 

 found in deep water, about 16 fathoms, and therefore living under 

 quite different external conditions of life. 



After this introductory account of what was hitherto known 

 about this plant I shall now give a description of it in more detail. 



At first I referred our plant to the genus Ckrysymenia, to 

 which it is also very closely related, but after a more thorough 

 examination it showed rather essential differences. Firstly, I may 

 here mention the diaphragms occurring at the narrowings of the 

 thallus (Fig. 11 C and Fig. 12^), by means of which the cavity in 

 the interior is divided into as many spaces as there are joints. 

 Further, the gland-cells occurring in the cavities on the inner side 

 of the membrane are sitting on some characteristic, irregularly 



1) "Crociera del Corsaro alle Isole Madera e Canarie del Gapitano Enrica 

 d'Albertis". Alghe per Antonio Piccone. Geneva 1884. 



