APPENDIX 



489 



tures (Fig. 211). Other spores (conidia) are borne upon the 

 ends of stalks (Fig. 212). These stallcs may be uncovered, 

 naked, or they may be inclosed in pycnidia (Fig. 213). Several 

 spore forms may be borne by one and the same fungus. The 

 mode of spore formation, the time and place, are important to 



Fig. 212. — Conidia 

 and conidiophorc 

 of powdery mil- 

 dew. 



Fig. 213.- 



- A pycnidium. Redrawn after Quartance and 

 Shear. 



the pathologist, for they may reveal a vulnerable point of attack 

 in the life history of the parasite. 



Bacteria, physiologically, are much like fungi, but their bodies 

 are single-celled and not threadlike (Fig. 214). They are very 

 small, — one of ordinary size is about 0.001 mm. long (j^m-^ inch) ; 

 yet they multiply with such rapidity (one produces a progeny of 



