8G JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



sufficiently early, spraying with potassic sulphide will check the 

 spread of the summer- spore condition, and consequently prevent 

 the formation of winter-spores, which remain dormant during 

 the winter, and germinate the following spring just about the 

 time when the leaf-buds have expanded. Diseased leaves that 

 have fallen should be collected and burned, otherwise the resting- 

 spore stage will develop on the dying leaves. All mildewed 

 twigs and fruits should also be cut away, otherwise the resting- 

 sporea or winter-spores which are developed on these parts will 

 with certainty renew the disease the following spring. The 

 entire life of the fungus is spent on the rose tree. 



Velvety Mould. {Sclcrotinia Fuckcliana, Be Bary.) 



This fungus has two very different looking kinds of fruit. 

 The summer condition, which is the commonest of the two, is 

 often called Botrytis cinerea, and appears under the form of an 

 olive-coloured or brownish mould, which forms a velvety layer 

 on almost every kind of dead or decaying vegetable matter. 

 Unfortunately this mould also attacks living plants, and of late 

 years has frequently proved a serious pest to vines, appearing 

 on the leaves, young shoots, and also on the inflorescence. The 

 mycelium of the fungus lives in the tissues of the host-plant, 

 and the external mould consists of myriads of upright stems 

 which are branched above, each branchlet bearing a cluster of 

 summer-spores at its tip. These spores are produced with great 

 rapidity, and possess the power of germinating as soon as 

 mature, consequently the disease spreads rapidly after its first 

 appearance, unless stringent measures are resorted to, to check 

 its progress. As already stated, this condition of the fungus 

 can live and produce fruit on dead as well as on living parts of 

 plants ; consequently, when all the leaves of the vine or other 

 plant on which the fungus was parasitic have disappeared, the 

 Hummer-spores germinate and grow on dead leaves or any frag- 

 ments of plants lying about, and by this means keeps itself 

 going until the young leaves of its host again appear, when they 

 are promptly attacked. Every gardener must be familiar with 

 this grey mould as it occurs on the branches of geraniums and 

 various other plants that have died back, also on dead, dried up 

 leaves, &C, on the soil of plant pots and on the ground. Under 



