478 



xhb bbb-kbepbr'S guide ; 



cholera, smallpox, etc. — are now known to be due to micro- 

 scopic germs, and hence to be spread from home to home, and 

 from hamlet to hamlet, it is only necessary that the germs or 

 the contained spores, the minute seeds, either by contact or by 

 some sustaining air current, be brought to new soil of flesh, 

 blood, or other tissue — their garden-spot — when they at once 

 spring into growth, and thus lick up the very vitality of their 

 victims. The huge mushroom will grow in a night. So, too, 

 these other plants — the disease-germs — will develop with mar- 



FiG. 261 



Middle iSiage. Late Stage. 



Foul Brood. — From A. I. Moot Co. 



velous rapidity ; and, hence, the horrors of yellow fever, scar- 

 latina and cholera. The foul-brood Bacillus, like all bacilli, 

 is rod-shaped (Fig. 261). The spore develops in one end, which 

 becomes slightly enlarged. 



To cure such diseases the microbes must be killed. To 

 prevent their spread they must be destroyed, or else confined. 

 But as these are so small, so light, and so invisible — easily 

 borne and wafted by the slightest zephyr of summer— this is 

 often a matter of the utmost difficulty. 



