328 FIRST FORMS OF VEGETATION. 
Professor Tyndal, by calling in the aid of optical 
analysis, has made assurance on that point doubly 
sure. If we venture for a moment to imagine the 
overwhelming number of seeds which the different 
species of fungi must disseminate in the course of 
a single year,—if we consider that each individual 
of the common puff-ball contains upwards of ten 
millions of seeds, and these so small as to forma 
mere cloud when puffed into the air, and that a 
single filament of the mould which infests our 
bread and preserves will produce as many germs 
as an oak will acorns, so that a piece of decaying 
matter, not two inches each way, will scatter upon 
the air, at the slightest breath of the summer 
breeze, or the gentlest touch of the smallest in- 
sect’s wing, as many seeds, quick with life, as this 
country will produce of acorns in a twelvemonth ;— 
if we take these things into consideration, it is not 
too much to suppose that the seeds of fungi must 
be ubiquitous, and from their excessively minute 
size penetrate into every place, even into the 
stomachs and other parts of animals. Indeed, the: - 
difficulty seems to be rather to imagine a spot 
altogether destitute of them than to account for 
their universal diffusion. This circumstance has 
been made the ground of a belief that malarial 
and epidemic fevers have their origin in crypto- 
gamic vegetables or spores. Much valuable infor- 
