I 101 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



NOTES <>X RECENT RESEARCH. 



Aui.K. 



Alg-ae (Siphoneee) (Beih, Bot, Cent, bd, xiii, ht. 1, pp. 115 L48, 

 pis. vi. x.). Heir A. Ernst (Zurich) gives u full description of a new 

 genus Uichotomosiphon tuberosum, formerly known as Vaucheria tnherosa, 

 Braun. The hyphee show diohotomous branching, and characteristic 



constrictions ; then* is a very full account of the starch grains, chlorophyll 

 bodies, and reserve substances. The oogonia are terminal. The an- 

 theridia are *2 4, and the oogonia solitary or in pairs. The latter are 

 2{)() Mir> /( along the long diameter, and 27f> '2H0 across. The plant 

 when grown on wet soil often forms tubercular swellings from 0'5 5 m. 

 long and (>2 01 mm. broad. These are full of protoplasm, chlorophyll, 

 and starch, and are of a. dark green colour: new filaments are given off 

 h\ these tubercles. The plates are exceeding well done. — G. F. S,-E, 



I luminous Bacteria. 



Bacteria, On Luminous. Note by J. E, Barnard and Allan Mac 



fadyen (Ann. Bot, vol. xvi., No. 64, p. 587). Abstract of paper read 

 before Section K of the British Association, Belfast, 1902. " These 

 organisms are to be found mainly in sea- water and on dead marine 



animals \bout 25 varieties have been described, but it is probable 



that some of these are very closely related, if not identical. A hitherto 

 undescribed form has been is dated from sea-water in the course of 

 investigations made by one of us at Plymouth. . . . The luminosity of 

 the sea is mainly due to higher forms of marine life and not to luwlrna, 

 at any rate in northern Latitudes. On the other hand, tbo phosphor- 

 escence of dead objects, such as fish, &C, is due to bacterial forms of life. 

 . . . The luminosity appears to be a function of the living cell, and can 

 be disturbed by any process which interferes with the vitality of the cell 

 itself. The dead eel) is non-luminous, while antiseptics which kill the 

 cells inhibit at the same time their luminosity. . . . There is no evidence of 

 ;i bacterial product as the source of light. The process appears to be the 

 result of an active oxidation occurring within the cell. The light pro- 

 duced is confined to a small portion of the visible spectrum, and Invisible 

 radiations have not been detected. The light is produced without heat. 

 No invisible radiations allied to the X-rays were detected. Photographs 

 have been obtained by the aid of the light emitted by these organisms. . . . 

 An exposure to the temperature of liquid air does not destrviy the lumi- 

 nosity of the organisms. . . . The luminous Bacteria mechanically broken 

 up . . . ceased to phosphoresce. The luminosity, therefore, is due to tho 

 \ital processes of the cell, and essentially depends for its origin on the 

 intact organisation Of the cell. We have brought these results forward 

 because this interesting group Of organisms have not hitherto been studied 

 m this country B0 far as we can trace."— /k /. L. 



