PEZIZALES 



323 



S. Linhartiana on quinces, S. fructigena on apples and pears, S. laxa on 

 apricots and S. cinerea on cherries, plums and peaches. 



In Sclerotinia Urnula, the young shoots, infected in the spring, become 

 brown and dry. In their rind, appears a stromatic fungus tissue which 

 sends through the cuticle simple or dichotomously branched conidiophores 

 and cuts off on them moniliform, oidial, citriform, hyaline conidia, smell- 

 ing like almonds; thus the diseased branches appear mouldy. The conidia 

 were early placed in Monilia. At first they cling firmly together with 

 their flat septa. Later these septa split into two lamellae each of which 



Fig. 213. — Sclerotinia Urnula. 1. Young conidial chain. 2. Older stage showing 

 fundaments of disjunctors. 3. Mature conidial chain. 4. Germinating conidium with 

 germ tube beginning to sprout. (X 345; after Woronin, 1889.) 



detaches in the middle (mutatis mutandis, somewhat as in Albugo) a small 

 conidial plug (Fig. 213). Both plugs form a fusiform body, thedisjunctor. 

 Hence the connection between the conidia has become very loose. When 

 they are touched by insects they cling to them and thus reach the stigmas 

 of their host. Here they germinate to mycelia which, like pollen tubes, 

 penetrate the stylar canals and ovaries, even to the surface of the berries 

 and change them to longitudinally ribbed, brownish, sclerotic mummies. 

 These mummies fall to the ground and winter over. Directly after 

 a thaw, the erupting ascigerous fructification bears an apothecium as 

 broad as 1 to 1.5 cm. on a 2- to 10-cm. long brown stipe, hairy at the base. 

 The ascospores are shot out with great force and, in case they reach the 

 young shoots of the billberry, develop to the above described mycelium. 



We find a similar life cycle, especially a similar rhythmic change 

 between moniliform spores provided with disjunctors and apothecial 



