282 SUMMARY OV CURRENT RESEARCHES RELATING TO 



forme; IG. S. Jimhrialum ; 17. S. Girgenaolmii ; 18. S. Wuljii ; 19. 

 S. sqiiarrosum ; 20. S. teres; 21. S. Lindbergil ; 22. S. recurvum ; 

 23. S. ripariiim ; 24. S. cnspidatum. Under luauy of the species a 

 very large number of forms are enumerated, classified according as 

 tbey are more or less casspitose, or of stouter or more delicate 

 growth. 



Radula.* — F. Stephani enumerates all the sjiecies of Badula at 

 present known, and describes a large number of new ones from dried 

 collections from all parts of the world. The organs of fructification 

 being remarkably uniform in the genus, the best characters for classi- 

 fication are obtained from the vegetative organs, and especially from 

 the leaves in relation to their lower lobes. In some species this lobe 

 is quite inconsiderable, while in others it is develoi^ed in very 

 characteristic forms. The following are the 12 groujjs into which 

 Stephani arranges the 110 known Rjiccies of the genus: — (I) Aciiti- 

 folice; (2) Macrohhce ; lobuli maximi caulem valde superantes. (3) 

 Ampliatai ; lob. pars libera ampliata sujira caulem i>rotracta. (4) 

 Communes ; lob. subquadrati canli parum incumbentcs. (5) Javanicce ; 

 plantse pro more spectabiles. (6) Microlohce ; lob. parvi, subquadrati, 

 cauli parum incumbentcs. (7) Plumulosce ; lob. parvi, pro more 

 subtransverse adnati, rotuudati, ramificatio distincte pinnata. (8) 

 Saccatilohoi ; plantaa pusillae, arete repontes. (9) LoncjiloboB ; lob. 

 elongati, axi cauli parallelo. (10) TumidcB ; lob. plus minusve inflati, 

 axi carinfe parallelo. (11) Amenfulosce. (12) Cavifolice. 



The region of tropical America is distinguished by species with 

 strongly developed lower lobes ; the Antarctic region by species with 

 large hollow lobes ; that of tropical Asia and Oceania by one of the 

 most difficult grouj^s of the genus in consequence of the great simi- 

 larity of the species belonging to it. 



Algse. 



Chlorophyll of Fucaceae.t — According to A. Hansen the coloured 

 leucites of Fucacete contain chloroi^hyll and xanthophyll in the same 

 proportion as the higher plants, and their physical properties, in 

 Funis vesicidosus, are the same as in flowering plants. The spectrum 

 of the chlorophyll presents four absorption bands in the red, and that 

 of tlie xanthophyll three in the blue. The brown pigment, or phyco- 

 phtein, the function of which in assimilation is at present unknown, 

 gives one absorption band between Fraunhofer's E and F. 



To criticisms in this paper directed against some of the observa- 

 tions of A. Tschirch, the latter replies.^ 



New Instance of Symbiosis.§ — C. di Marchesetti describes a case 

 of symbiosis between an alga and a sponge from the Gulf of Singapore ; 

 the compound organism having been described by Hauk as an alga 



* Hedwigia, xxiii. (1884) pp. 113-6, 129-37, 145-59, 161-3. 



t SB. Phys.-med. Gesell. Wurzburg, 1884, pp. lOi-6. See Bot. Ztg., xlii. 

 (1884) p. 649. 



X Bot. Ztg., xlii. (1884) pp. 817-20. 



§ Marcheietti, Carlo di, ' Sur un nuovo caso di Simbiosi.' See Oestcr. 

 Bot. Zeitschr., xxxiv. (1884) p. 337, 



