ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
467 
allowed of a very luxuriant growth. Between the D and E lines of the 
spectrum there was no perceptible diminution of growth ; between E 
and F the inhibitory effect became apparent, and in the blue, violet, and 
ultra-violet parts of the spectrum the plates were perfectly sterile. 
That the light-rays have a direct unfavourable action on the bacteria 
and not on the media, is shown by first exposing the media to the light 
and inoculating them afterwards, the development of the colonies being 
quite the same as when the media were inoculated beforehand. 
Prof. H. Marshall Ward* * * § publishes full details of his series of 
experiments on the action of light on bacteria. He arrives at the 
general conclusion that the injurious action of light is probably common 
to all the lower forms of vegetable life, and even to all living protoplasm. 
Fossil Bacteria.! — In addition to the species already described, 
M. B. Kenault finds two fresh ones in the silex of Grand’ Croix, which 
he names Micrococcus Guignardi and 31. Tiymenophagus ; these have 
attacked chiefly the cellulose of vegetable cells. The former was found 
in the interior of the wood of Calamodendron , in roots, and in the integu- 
ments of seeds, on the cell-walls ; the latter in the intercellular spaces 
and on the middle membrane ; the cuticle is not attacked. 
Cell-contents of Bacillus oxalaticus.J — For observing cell-contents, 
Bacillus oxalaticus Zopf, says Herr W. Migula, is a very favourable 
object on account of its size. In the middle of the cells there is visible, 
even without staining, a clear space which resembles a vacuole, and this 
was demonstrated by plasmolytic experiments conducted with the greatest 
care. In this respect the bacillus differs from the Alga-Schizophytes 
which possess a nucleus resembling a filament. The author also com- 
municates some observations on the division of cells. In young cells 
the plasma appears to be quite homogeneous, while later on small highly 
refracting granules and a clear spot (vacuole) appear in the centre. The 
granules are arranged as a ring-shaped zone along the wall, and from 
this there is formed a plasma bridge which divides the vacuole. With 
the continued enlargement of the cell, the division of the vacuole becomes 
more marked. Later on, traces of the future septum arise from the 
ring-shaped granular zone. 
Cilia of the Microbe of Hog-Cholera.§ — M. Ferrier finds that the 
liog-cholera microbe possesses flagella as long as 35-55 p, the length of 
the organism being about 1 p. The number of the cilia is from four to 
seven. The author states that there is no mention in any work of the 
cilia of hog-cholera microbes, but they are beautifully shown in Stern- 
berg’s ‘Bacteriology,’ 1892, p. 444, pi. vi. 
Cladothrix invulnerabilis.|j — Dr. E. Acosta mentions the fact that 
Gladothrix invulnerabilis is resistant to drying and keeping. A potato 
* Phil. Trans. Roy. Soc., clxxxv, (1895) pp. 961-86 (1 pi. and 23 figs.). Cf. this 
Journal, ante. p. 215. 
t Comptes Rendus, cxx. (1895) pp. 217-20. Cf. this Journal, ante, p. 346- 
+ Arb. aus d. Bact. Inst. d. Teclm. Hocksch. zu Karlsruhe, i. (1894) p. 187. See 
Hedwigia, xxxiv. (1895), Rep., p. 5. 
§ Centralbl. f. Bakteriol u. Parasitenk., l te Abt., xvii. (1895) pp. 535-6. See 
Lyon Medical, 1894, No. 40. 
|| Cronica Me'd.-Quirur, Habana, 1894, No. 18. See Centralbl. f. Bakteriol. u 
Parasitenk., l te Abt., xvii. (1895) p. 465. 
