114 J. G. Ä.gardk 



vavit, fusius eam descripsit Ins verbis: „Francis at first globose, like tubers, 

 heaped together, hollow and empty or filled with sea water, attached to 

 the rock and to each other by a few short, rooting processes; at length 

 irregularly torn and then forming expanded, cartilaginous or skin-like 

 coarsely reticulated membranes. The membrane is wholly composed of a 

 single layer of large, globose, or by mutual compression hexagonal cells, 

 which closely cohere by their sides, leaving the convex ends of the cell 

 free, and these form the surface of the membrane". Quam eximie bis 

 verbis tum forma exteriör frondis evolutae, tum structura membranae sub 

 stadio adultiore descriptae ceuseantur, tarnen veram evolutionis normam 

 hac descriptione iuterpretatam fuisse vix putarem. Sequeutia observare 

 credidi. 



Sub statu maxime iufantili frondem, 2 — 3 lineas longam, vidi tubu- 

 losam (Tab. 11 fig. 1) et forma cylindraceam, deorsum prolongatam in 

 radiculam brevissimam, strictura parum conspicua sub-separatam; superiore 

 parte frondis minutae nomlum diaphragmatibus in cellulas subdivisa. Or- 

 gana, porös semulantia, qme in adultiore fronde secus diaphragmata cellu- 

 larum disponuntur, per totam longitudinem frondis tubulosae prassentia 

 vidi; hinc forsan conjicere liceat haue quoque fieri in cellulas quasdam 

 longitudinaliter superpositas divisam; revera quoque in nonnullis speeimi- 

 niljus adultioribus (ultra pollicaribus) observavi frondem rotundatam deor- 

 sum continuari in cellulas paucas, articulatim superpositas, 2 — 3, qua? quasi 

 stipite brevissimo frondem globosam sustinent. Nescio an assumere bee- 

 ret haec cylindracea initia aliquando magis evoluta fieri, et formam a 

 Montagne descriptam, quam speciem propriam consideravit, ejusmodi sta- 

 tum evolutionis referre. Ut plurimum vero frondem parte sua inferiore 

 supra rupes expansam esse, et ex parte dilatata inferiore numerosas agere 

 radiculas filiformes et tubulosas, satis constat. Quamquam frondem infan- 

 tilem supra descriptam, nunc superne vesiculoso-inflatam observaverim, 

 tarnen formationem cellularum initialium observare mihi non contigit. 



Plantam paulo magis evolutam, at adhuc juvenilem, magnitudiue dru- 

 pam minorem Cerasi circiter a?quantem, vidi totam cellulosam et solidam; 

 nimirum non tantum extrorsum in cellulas plurimas minores subdivisam, 

 sed quoque in inferiore sua parte cellulis numerosis compositam. Cellulas 

 inferiores paulo majores et quoquoversum angulatas dicerem ; caeterura 



