ZOOLOGY AND BOTANY, .MICROSCOPY, ETC. 723 



ZOPF, W. — Zur Kenntniss der Flechtenstoffe. (The knowledge of Lichen con- 

 stituents. Sixteenth contribution.) 



[A number of new acids have been isolated.] 



Licbig's Ann. Chemie, ccclii. (1907) pp. 1-44. 

 See also Bot. Centralbl, cv. (1907) pp. 143-5. 



Schizophyta. 

 Schizomycetes. 



Two New Purple Bacteria.* — H. Molisch describes two new purple 

 bacteria : 1. Rhodocapsa suspensa appeared in a glass vessel containing 

 seaweed, a dead crab or star-fish, and sea-water from Trieste, that had 

 stood in full daylight for some months, the water being stained a rose- 

 red colour. If examined in sea-water, no trace of a capsule is visible, 

 but if Indian ink is allowed to flow under the cover glass, a colourless 

 halo is seen to surround each of the bacteria. The organisms vary- 

 greatly in length from 0-5/* to l<sO/x, being usually l(i/x to 20/1. ; they 

 appear as rods or as more or less curved threads, in which are seen 

 curious highly refractile bodies, that give an irregularly segmented 

 appearance to the cytoplasm. The organism can be stained by aqueous 

 solutions of aniline dyes, and the capsule stains well with Peppler's 

 flagella method. In the swarming state when the capsules are absent, 

 the bacteria show active motility, but in the resting capsuled state this in 

 not seen ; spore formation was not observed. The refractile bodies, 

 which the author refers to as "airosomes" (" Schwebekorpchen "), dis- 

 appear on pressure and on drying, and by the action of the vapours of 

 alcohol, chloroform, ether, etc., and of weak solutions ' of alkalies and 

 acids. These bodies are distinct from sulphur granules, which can also 

 be detected in these bacteria. 



2. Ehodofhece pendens ii])^Q-Are({ in a vessel containing marine algte 

 and sea-water from Heligoland, that had stood in the daylight for sis 

 months, the fluid having acquired a rose-red colour. Examined by the 

 Indian ink method referred to alcove, it was found that each bacterium 

 was surrounded by a round or elliptical colourless halo. The cells 

 contained sulphur bodies and red highly refractile airosomes like those 

 seen in Rhodocapsa. The organism appeared as a large round coccus, 

 giving rise on division to diplococci and short chains ; the cells without 

 their capsules varied from 1-8-2-o/a in diameter. Active motility 

 was never observed. 



Nitrogen-fixing Organisms in the Sea-water of the Gulf of 

 Naples.f — W. Benecke disproves the assertion of A. Xathansohn that 

 nitrifying and nitrogen-fixing organisms do not occur in the water of 

 the Gulf of Naples, and that therefore the part that these bacteria are 

 considered to take in the metabolism of the sea has no existence. The 

 author obtained samples of water from the sea bottom, at depths vary- 

 ing -from 20 to 100 m. ; these were added to sterile nutrient solutions 

 containing 1 to 2 p.c. mannite, and 0-02 p.c. potassium phosphate 



* Bot. Zeit., xii. (1906) p. 31. 

 t Ber. Deutsch. Bot. Gesell., xxv. (1907) p. 1. 

 Bee. 18th, 1007 ;->, b 



