FUNGI. 



247 



pocket lens, will be seen to have been split at the 

 apex, with the torn edges turned back like a white 

 fringe, surrounding a central orifice of a golden-yellow 

 colour. By using a higher magnifying power, the 

 yellow centre is found to be caused by a mass of 

 globose bodies, called spores, or cscidiospores, nestling 

 within the little white fringed "cluster cups," which 

 latter have their base imbedded in the purple stratum. 

 The purple spots are appreciably thicker than the 

 other parts of the leaf, and this thickening is caused 

 by the mycelium, or rooting filaments of the cluster- 

 cups beneath the cuticle. Hence, be it observed, 

 the parasite consists of an innate 

 mycelium, from which the cluster- 

 cups are developed, each one consist- 

 ing of a white cup-shaped peridium, 

 or conceptacle, containing numerous 

 globose, yellow aecidiospores. If 

 examined at a sufficiently early 

 period, these secidiospores will be seen 

 to arise from the basal cells of the 

 cup in parallel chains, the apical one 

 breaking away consecutively when 

 mature, and becoming free within the prc. 49.-Germinatioii 



rr-i • • ,1 r 1^ L T^i of aecidiospore. 



cup. Ihis is the first stage. Ihe 

 resulting spores are capable of germination and repro- 

 duction (Fig. 49). 



Later on, from the end of April until early in June, 

 the same, or other, leaves will exhibit little orbicular 

 pustules, scattered over the whole surface, each one of 

 which splits in an irregular manner, and discharges a 

 cinnamon-coloured powder, which is soon sprinkled 



