ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 277 



pagation and cultivation in fluids had been without result. It is worthy 

 of remark that within the gelatinous masses small colonies of Gloeocapsa 

 were invariably present. The constancy of their appearance indicates 

 that this symbiosis is a mutualism or co-operation of functions of the two 

 organisms such as exists in lichens between fungi and their attendant 

 algai. The settlement of the Glaiocapsa is favoured by the softness and 

 moisture of the zoogloea, while in its turn it supplies the bacillus with 

 oxygen, and receives in exchange carbonic acid. 



With regard to the species of Gloeocapsa, it may be remarked that at 

 the edge of the zoogloea, where it occurs without bacteria and forms 

 blue-green rosettes, it corresponds to G. polydermatica Ktz. ; in the 

 zoogloea layer, where the blue-green hue is fading, with G. fenesiralis ; 

 and where it is quite decolorized, and the envelope become brown, it 

 appears as G. fusco-lutea. Perchance other organisms may be included in 

 the zoogloea, e. g. protonemata of mosses. It is accordingly probable that 

 bacteria occur with alga? in a symbiosis based on reciprocity of functions, 

 and which promotes their mutual benefit. 



Dr. A. Hansgirg * is convinced, from having examined the material 

 presented to him by Tomaschek, that the Bacillus muralis is a form of 

 Aphanothece caldariorum Richter, which Richter and Zopf declared to 

 be a bacillus form of Glaucotlirix gracillima Zopf. The Gloeocapsa 

 forms described by Tomaschek have been known for a long time to 

 writers on Algai, but under other names. 



Bacteria in Hailstones.| — Dr. 0. Bujwid relates how in May 1887, 

 there fell at Warsaw during a storm, hailstones 6 cm. long and 3 cm. 

 thick. He washed one of these thrice in sterilized water, and then, 

 having broken it up into pieces 2-3 cm. in size, placed these in a test- 

 tube, and then washed again three times with sterilized bouillon. After 

 this there remained some water, with 1 cm. of which he inoculated two 

 plates. In two clays numerous colonies had grown in both plates, and 

 had partially liquefied the gelatin. By means of Wolffhiigel's appara- 

 tus 21,000 bacteria to the ccm. were counted. Certain of the colonies 

 had a different aj>pearance, and from twelve of these gelatin tubes were 

 inoculated. In a few days there developed Bacillus fluorescens-liqiie- 

 faciens, B. fluorescens-putridus, a mixture of rods and short Bacilli, which 

 liquefy gelatin and form a dark violet scum on the surface. The latter 

 form in a jar at the ordinary temperature whitish-grey colonies, which 

 in two to three days assumed a blackish-violet hue. 



Apparently this kind of Bacterium is none other than the Bacillus 

 janthinus described by Zopf. The author had never found this in water 

 from Warsaw and its neighbourhood. And as the foregoing bacteria are 

 only found in foul water, he assumes that the water was taken up by 

 the wind and deposited as hailstones at Warsaw ! 



Phosphorescent Bacillus. J — Dr. B. Fischer, who has already de- 

 scribed two phosphorescent micro-organisms in Bacillus phosphorescens 

 and Bacterium phosphorescens, gives the following account of a third 

 light-developing Bacillus which he has found to inhabit the water of 

 the Baltic Sea : — 



The number of germs to the cubic centimetre of water varies from 

 4 to 20. It was also obtained from raw herrings, to which, along with 



* Bot. Centralbl., xxxiii. (1888) pp. 87-8. 



t Centralbl. f. Bukteriol. u. Parasitenk., iii. (18SS) pp. 1-2. 



X Ibid., pp. 105-8, 137-41. 



