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gL-inch and the highest eye-pieces that we can hope for any 
useful result. And, furthermore, as Mr. Dallinger has pointed 
out, most careful and continuous observation must he carried 
on. Assuredly if he (Mr. Dallinger) had not adopted the con- 
tinuous method of study, he would have described as three 
or more distinct individuals what were merely the successive 
stages of development of one and the same being. It is almost 
absurd to see, as we do, in the controversy which took place 
some few years ago between M. Pasteur and M. Pouchet, refer- 
ence to the employment of a power actually of 150 diame- 
ters !! ! Why, a power of 150 diameters would be altogether 
inadequate to such labours as those that are demanded; it 
would be as much, and even more, out of place than Malpighi’s 
lenses would be if compared with the powers of the microscopic 
anatomist of to-day. 
As to the second point of inquiry, that has been much less 
fully worked out. Although Mr. Blackley and a few others 
have attempted to show the immediate connection between 
disease and microscopic organisms, much less has been done 
than the subject demands. And there can be no doubt that it 
only awaits some one who, like Mr. Dallinger, will bring intense 
patience and the highest powers of the microscope to bear on 
it, to enable the subject to be completely cleared up. 
At all events, we can congratulate the workers on the 
useful labour that they have given to the subject, and we must 
only hope that in a few years more, we shall be able to see more 
clearly that immense surface which is now as it were a barren 
plain with an immensity of exquisite mirages spread above it. 
