124 PEOGEESS OF MICEOSCOPICAL SCIENCE. ["Jom^nl Fe^lTS^^ 
siders almost essential for good results. Of course it has tlie dis- 
advantage of not providing any means for the continuous observation 
of progressive development, as the results of the cultivation in it can 
only be examined on breaking open the flask. 
2. The small apparatus : This consists of a small bell-glass, com- 
municating with the air by a bent tube, and standing in a basin of 
permanganate of potash. In this, as described in the " Gahrungs- 
Erschinungen," the substance to be cultivated is made to rest on a 
small glass or earthenware dish, so as to keep it out of the perman- 
ganate solution. 
II. The substrata which Professor Hallier employs. 
1. The freshly exposed pulp of lemon, " which, as freshly exposed, 
may be presumed to be free from spores or fungal elements." 
2. Thick starch paste, containing some salt of ammonia. 
3. Solution of grape sugar. 
4. Cork which has been previously soaked in alcohol. This is 
carefully dried, and " when employed as a substratum is kept so, but 
surrounded by moist air." 
5. Fresh potato. 
In making a series of observations on development, he employs 
the large apparatus for getting fully developed results, and several of 
the small ones for results which may be frequently examined, and so 
show the steps of development. 
In making any series of observations, two pieces of lemon, cork, 
&c., should be employed, on one of which spores are sown, and on the 
other they are not, so as to be able to compare the one piece with the 
other. 
III. A summary of Professor Hallier's view as gathered from ex- 
planatory statements made whilst demonstrating his preparations of cholera 
stools, dc. — Professor Hallier stated that the fundamental idea of the 
whole theory is that " moulds are mere unripe forms of ustilagines." 
This is a view of his own, and is not generally recognized. He believes 
that any fungus of this series may appear under various forms ; these 
forms depending on the nature of the substratum, and on the degree 
to which ripening goes on. If the spores of an ustilago be cultivated, 
two forms always appear — viz. the schizosporangic and the cladosporic 
forms ; if the soil on which any of these forms appear alters or fer- 
ments, the forms produced are different. He states that each species 
of ustilago has three ripe formg of fructification, and that each of these 
has a corresponding unripe representative, the use of the unripe form 
being probably, according to Professor Hallier, to prepare a more 
nitrogenized soil on which the highest forms may be developed. " If 
Tilletia caries be cultivated on weak, poor soil, we get only unripe 
forms — i.e. moulds make their appearance." 
These ripe and unripe forms may be thus tabulated, taking as an 
example the fungus associated with cholera : — 
Unripe. Ripe. 
1. Macroconidia. 
2. Penicillium crustaceiim. 
3. Miicor racemosus. 
1. Tilletia caries. 
2. Cladosporium. 
3. Schizosporangiiim (cholera cyst). 
