FUNGOUS DISEASES OP TSE CAENAlION. 



335 



much as does the well-known "fairy ring." The myce- 

 lium developing within the tissues causes them to take 

 on a light yellow color. Just beneath the epidermis, 

 dark brown swellings appear upon the mycelium, from 

 which the fruiting threads (Fig. 119) are sent out 

 through the cuticle. These are produced in great num- 

 bers from a single spot and gives it a dark brown appear- 

 ance. A single spore (Fig. 130) Is produced at the 

 extremity of each thread ; these are generally four- 



^% 



FIG. 119. PAIET KEfG SPOT OF CJB- 



IfATION, FRUITING THREADS. 



(Greatly magnified.) 



FIG. 120. SPORES OF FAIBT SPOT. 



6 Spores germinating 



(Greatly magnified.) 



celled, but may vary from one to five, and are covered 

 with minute spines. Germ tubes (Fig. 120, B) may be 

 sent out from each cell of the spores. The mycelium 

 continues its development and finally forms another set 

 of fruiting hyphae, generally in a circle around those 

 first produced. In this way the disease can be distin- 

 guished from the carnation rust, with which a carelesa 

 observer might confound it. 



