164 THE MICROSCOPE. 
ally agree that starch is not found in plants other than those con- 
taining chlorophyle, and that the presence of the latter, together 
with sunlight, is necessary for the manufacture of starch. What the 
starch-bearing fungus has to do with caries he does not say, but 
would it not have a great deal to do with the value of his conclusions 
generally ? It would certainly be a fine thing to discover granules 
of starch in these minute organisms, and if they were there, it would 
be for use of the plant, not to ferment an acid for cutting the 
teeth. 
Dr. Miller thinks he has seen baccilli in the dental tubuli. 
What he has seen I am convinced is nothing more than the contents 
of the tubules shrunken by the reagents he used so as to break into 
nodules, which being stained might be mistaken for an organism of 
that kind. 
This investigator says: ‘I have been able to obtain sufficiently 
thin sections of fresh dentine in an advanced stage of decomposition 
to observe and study the action of the fungi and see the tubules 
filled with micro-organisms in active motion.” He must certainly 
be mistaken, for even if he succeeded in getting his sections without 
destroying all life, the liquids he would have to use to produce suffi- 
cient transparency would destroy the life of any specie of fungi. 
Besides a staining fluid would be necessary to show such organisms, 
and such as are used for staining bacteria are fatal to life. He 
describes but one method of preparing his specimens, which, while 
it is good enough for all ordinary purposes, its use would destroy 
the life of any species of bacteria. 
It is the ordinary method of preparing such objects for the 
microscope. He passes them from alcohol to the staining fluid, then 
to the mounting medium. The very first step would kill.- There 
are, I admit, cases on record of some very highly organized beings 
able to withstand large quantities of that liquid when taken internally, 
but when applied to the outside in any considerable quantity it is 
fatal. Might it not be that Dr. Miller has mistaken a glimmer that 
sometimes comes before the eyes on looking through the microscope, 
for living organisms? 
He finally claims to have met with one kind of fungi, ‘‘ which 
beyond all doubt, has the power of boring directly into sound den- 
tine.” He says, ‘‘it appears to generate an acid upon its growing 
extremity by means of which it eats its way into the hardest dentine.” 
And what is more wonderful, it does not even follow the dental 
tubuli, but cuts across in any direction, preferring the most impos- 
sible method. This is a very remarkable discovery. It would be 
