302 THE MICROSCOPICAL NEWS. 
acid mixture does not kill the existing bacilli, but prevents their 
further development. There seems to be still a prospect, therefore, 
that the world will have reason to be grateful to the German Go- 
vernment for sending a cholera commission to India, and to Dr. 
Koch for his discovery of the “comma” bacillus. 
OUR BOOK-SHELF. 
Our Insect ALLIES. By Theodore Wood. London: Society 
for Promoting Christian Knowledge. 
This very pleasing little volume which, we trust, will serve for 
many a Christmas present to those who have just commenced the 
use of the microscope, is intended to show us that many insects 
which we have been led to regard from our youth up as injurious 
to mankind are really helping in the great work of Nature. The 
author remarks with truth that some few insects are more fortunate 
than their fellows, and are protected by a superstition which makes 
it “unlucky” for any one to harm them. This is quite correct, 
but why some should be thus favoured it would be a puzzle to 
indicate. 
There is no doubt if we knew, and knew perfectly, that every 
insect has its apportioned work set for it in Nature’s workshop, 
and if devastation occurs amongst our crops or in our stores, may 
not it be due to something we have done, or to something we have 
omitted? and, in this way, may we not have upset the balance of 
nature? Little things, so small indeed as to be entirely overlooked 
by the majority of observers, often effect complete revolutions when 
allowed to pass undisturbed. 
Does not the progress of civilization, as we are prone to call it, 
often scar the face of this fair earth with such seams as will take 
centuries to repair? On page 20 our author writes :—“‘ Let us take, 
for example, the Locust. We can scarcely imagine from our point 
of view a more terrible enemy than this insect which, appearing in 
countless myriads, leaves the country over which it passes as bare 
of vegetation as though it had been scorched by fire.” 
O man! thou little thinkest how the locust may look at thee, and 
how thou appearest under his eye. 
Not a century ago, the country near to Widnes or Runcorn gap 
was a beautiful damson growing district, and the gardens of Parr 
Hall in St. Helens were objects of beauty, but civilization has fallen 
on the spot, the world must have soda, and alkali, so ’tis said, and 
