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SUMMARY OF CURRENT RESEARCHES RELATING TO 
in nature, but he has been gradually forced to regard it as bacterial. 
It forms hemispherical or cushion-shaped masses, of a brown colour, 
attached to rocks in shallow water, and has a superficial resemblance to 
a sponge. The author considers various possibilities, — that it may be a 
bacterial mass like that of Crenothrix Kuhniana , or something like the 
calcareous pebbles formed by ScJiizothrix fasciculata as described by 
Murray, or a symbiosis between bacterial filaments and a gigantic 
Rhizopod. Apart from the Bacteria, there seems insufficient evidence 
to show that it is an organism at all. 
Action of Rontgen Rays on Bacteria.* — Dr. R. N. Wolfenden and 
Dr. F. W. Forbes-Ross have shown that the action of the X-rays is 
stimulating to the growth of Bacillus prodigiosus. 
The rayed cultures grew better than the control cultures, and peculiar 
changes were observed in the pigment-forming powers of this microbe. 
The chief microscopic changes were growth in chains or strepto-bacteria, 
and spore-formation. 
Migula’s Bacteriology and the Classification of Bacteria.f — In the 
first volume of Prof. W. Migula’s work on the morphology, development, 
and classification of Bacteria, the system is given as follows : — 
Family I. Coccacese. 
“ Species ” 1. Streptococcus (one plane). 
2. Micrococcus (two planes). 
3. Sarcina (three planes). 
4. Planococcus (two planes ; flagella). 
5. Planosarcina (three planes ; flagella). 
Family II. Bacteriacese. 
“ Species ” 1. Bacterium ; no flagella. 
2. Bacillus ; flagella. 
3. Pseudomonas ; polar flagella. 
Family III. Spirillaceae. 
“ Species ” 1. Spirosoma ; no flagella ; rigid. 
2. Microspira. 1-3 polar flagella ; rigid. 
3. Spirillum. 5-20 polar flagella ; rigid. 
4. Spirochsete ; no flagella ; flexible. 
Family IY. Chlamydobacteriaceae. 
“ Species ” 1. Streptothrix. 
2. Cladothrix. 
3. Crenothrix. 
4. Phragmidiothrix. 
5. Thiothrix. 
Family Y. Beggiatoaceae. 
“ Species ” Beggiatoa. 
The chief points that may be mentioned as indicative of the line 
taken by the writer are, that the flagella are continuous with the investing 
membrane ; that arthrospores cannot be distinguished from ordinary 
vegetative cells ; and that germination may occur in three ways : (1) The 
* Lancet, 1898, i. p. 1752. 
t Jena, 1897, 368 pp. and 6 pis. See Nature, lviii. (1898) pp. 97-9. 
