144 Marshall Ward. — On the Characters , &c. 
precipitates, or merely a turbidity? What colour-changes, 
if any? 
In all cases, the development of gas-bubbles, odours, and 
so on should be carefully noted. The products of fermenta- 
tion or putrefaction may be left for special enquiry ; a remark 
which is by no means to be taken as undervaluing the 
enormous and ever-growing importance of such enquiry, but 
simply because the subject lies outside my present theme, 
and we must put a limit to the discussion. 
7. Finally, wherever possible it should be determined 
clearly whether the Schizomycete is pathogenic or not ; 
whether it induces special fermentations, or nitrification, or 
reductions ; whether sulphur-granules are deposited in its 
cells, or compounds of iron in its walls ; whether it can alter 
starch, cellulose, &c.; and whether it can live in ordinary 
waters and so on. The resistance of its spores to desiccation, 
high temperatures, isolation, the action of anti-septics, and 
so on, may also be mentioned as subjects for investigation. 
If we had answers to all these questions, with respect to 
the 650 odd ‘species’ of Saccardo’s Sylloge, it is pretty 
certain that some changes of importance would result, for no 
one can doubt that the great cause of multiple species has 
been growth under different conditions. If we could have 
every c species ’ that will grow on a normal gelatine at 20° C., 
compared on that medium and at that temperature, under 
like conditions, the advantage would be enormous ; and 
similarly with all ‘species’ which will only flourish in bouillon 
at 35 0 C., and so on. 
Bacteriology is, after all, a sort of microscopic horticulture ; 
and what we want is a kind of bacteriological congress to 
decide on the best standard methods of comparison and 
growth. When a form is once isolated, and growing under 
the best conditions, the' morphologist can then take it in 
hand and work out the details. I see no other way of 
emerging from the chaos the subject is now in. 
