282 THE MICROSCOPICAL NEWS. 
dued fashion as to be insensible, when all vital activity disappears 
in the cells, and they appear old, used up, and of deformed con- 
tour, becoming full of granulation; but if life is suspended it is 
not extinct, it is only an apparent death. If oxygen is allowed free 
access and the plant allowed to: live for a while exposed to its 
action, it takes a new lease of life and is able to start anew the 
fermentation of sugar.” 
This statement is very important, and to aid us in our opinions 
regarding the ginger-beer plant, I will show you a drawing of Pas- 
teur’s Mucor ferment (fig. 69), the right half representing the plant 
deeply submerged, while the left half corresponds to the vegetation 
but little submerged, and consequently having at its disposal a 
certain quantity of air, which, though insufficient for its ordinary 
growth, is still enough to prevent the plant from becoming quickly 
exhausted. 
Let us now see what appearance the ginger-beer plant presents 
under the microscope. When viewed with low powers, very little 
can be seen,—a 4, and the B eye-piece being the lowest power 
under which anything can be seen. With a 3th or 3th a very fair 
view of the substance can be obtained, but still it is very difficult to 
make out details, and it is only when we come to use the $th that 
a satisfactory view of the plant can be obtained. The best view 
undoubtedly is by use of the ;3,th, 3,th, or ;},th objectives, and in 
these observations I have chiefly used Leitz oil immersion ;'sth 
which is easy to use, as there is plenty of light and quite enough 
working distance for all ordinary purposes. 
You will see (fig. 70) there is but little doubt that the bulk of 
the so-called ginger-beer plant is made up of the Mucor ferment, 
