SCLEROTINIA. 



257 



leaves of Vaccinium Vitis-Idaea exhibit in spring a mould- 

 like coating, consisting of chains of lemon-shaped conidia. 



Woronin thus describes it : " In the outer layers of the cortex, 

 amongst the dying elements, a pseudoparenchymatous cushion is 

 formed, from which simple or dichotomously branched hyphae 

 grow out through the overlying cuticle. The individual members 

 of the chains of conidia are separated from one another by a 

 spindle-shaped piece of cellulose — 'the disjunctor.' " 



The disjunctor spoken of here is a spindle-shaped cellulose 

 body found between the single conidia; it easily breaks across 

 and so facilitates the breaking up of the chains of conidia 



Fia. 135. — Sckrotinia vaccinii on Vaccinium VitU-ldaea. Mummified Cowberries 

 in fresh condition and in the following May, after development of Pesiza-cups. 

 A, Chain of conidia united by diajunctors. £, Germinating conidium after treat- 

 ment with iodine ; the plasma has shrunk, but remains connected with the 

 sporidia in process of abjunction. (After Woronin.) 



■(Fig. 135). It has its origin as follows: The conidia at first lie 

 ■closely end to end, enclosed in a delicate primary membrane ; 

 the partition-membranes split into two lamellae, each of which 

 takes part in the formation of a cellulose body which gradually 

 becomes spindle-shaped. In the course of its growth this cellulose 

 body — the disjunctor — ruptures the primary enclosing membrane, 

 and, being released, becomes more elongated, so that the conidia 

 are pushed away from each other and fall apart. 



The conidia have a strong characteristic odour of almonds, 

 ■attractive to insects, which carry off the conidia and dust them on 

 the stigmata of other Vaccinium flowers. Wind is also, in all 

 probability, an agent in the distribution of the conidia. The 



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