24 

 Sometimes these widenings au:e close to each, other, and soxnetiines farther 

 apart. Out of these swollen points on one or both sides of the spores 

 there appear germ- tubes, ©le development of the germ- tubes uaa the same 

 spore is not uniform; single germ-tubes may have reached a considerable 

 length while others are still very short. Soon these gern>- tubes grow into 

 long, branched hyphae;. forming nycdiium of the sphaqelial stage. This takes 

 place in spring just T«toen the host plants are blossoming. The young n^rcelitim 

 coming from the ascospores forms numerous conidia at the ends of their 

 lateral branches. The conidia which are formed apically one at a time 

 arrange themselves sidewise on the stalk. They do not adhere in a chain but 

 each new conidium pushes the former aside and they remain in parallel groups 

 until jarred apart. Sterigmata are not to be differentiated. This uni- 

 formity becomes more marked when conidia are formed on nutrient media, as 

 a result of immediate germination of the conidia. The conidia, as already 

 mentioned, are themselves capable of immediate germination and of infecting 

 plants if carried to them when they are in blossom. The germinating 

 conidia may send out a single tube at one or at each end v/ithin six hours, if 

 conditions are favorable. Ehe newly formed mycelium soon becomes rounded at 

 the end, then continues to enlarge into an egg-shaped conidium. Two or more 

 conidia may be fonned at the same time. In such cases they lie length- wise , 

 on the side of the mycelium so as to make room for new conidia. The for- 

 nation of numerous conidia, however, is not always common. 



The nuclear division in the sphacelial stage goes on very 

 rapidly (109) Each nucleus divides; part of it passes into the newly form- 

 ed Conidium; the other part continues to grow and re-divides. Conidia may 

 be formed also on the side of the promycelium without being preceded by 

 ^ %.i^^ A ohnyt stalk only being projected on which the conidia are borne. 



