

GERMS IN THE AIR. 2 1 



and bear upon their summits heads in which spores 

 are formed, these last being so well protected from the 

 influence of destructive agents, that the germinal 

 matter within can retain its vitality for a great length 

 of time. Fig. 10, plate II. 



GERMS IN THE AIR. 



The spores just referred to are so light as to be 

 easily supported in the atmosphere, and they may be 

 carried a long distance by currents of air. The in- 

 finitesimal germs before adverted to are of course 

 transported still more readily. Some of these are 

 represented in Fig. I, plate L, and some of the most 

 minute that can be discovered with the highest powers 

 of the microscope, in Figs. I to 5, and in Figs. 13 and 

 14, plate II. Bodies weighing 100 times as much as 

 these can be supported in air. There is, therefore, no 

 wonder that germs so very small and light are 

 almost constantly present in our atmosphere. Myriads 

 no doubt perish for one that falls in a spot where it 

 meets with suitable food and other advantageous con- 

 ditions. It is not to, be wondered at that such minute 

 germs as these should exist almost everywhere, float- 

 ing in the atmosphere, deposited upon everything, and 

 ready to undergo development wherever the conditions 

 may be favourable. And the vitality of the bioplasm 

 of lowly organisms of the kind under consideration 

 is so great, that protected as it is by its external en- 



