TUi;ru< IMA. :;i'i 



ut'ter the promycelium becomes divided by <To->-septa in its 

 upper part, and the conidia tun are lYeipH'iitly divileil by one 

 or two septa. The two pmmycelial cells become detached. 

 while the conidia begin to fuse together 1,\ mean- of out- 

 growths near their base : thereafter each conidium givea 

 out a secondary conidium, into which tin- plasma-contents 

 pa~.s over. A similar formation of -secondary conidia may take 

 place without previous fusion of the primary conidia. The 

 conidia fall apart, and they, as well as the upper promyeelial 

 (Us thereby left isolated, ;j;row out as hyphae. li HIU-L be 

 these hyphae which infect the rudimentary shoots of Tr'nnhili* 

 when they are already partially formed for next year. The 

 resulting mycelium permeates the shoots in the following spring, 

 and branches of it emerge through the stomata. oi- pass between 

 the epidermal cells and break the cuticle, to -row up either at 

 once as conidiophores, or to form on the surface of the leaf a 

 web from which conidiophores ari-e. Tin- pear-shaped conidia 

 an- attached by their broader side, and easily fall off, leaving 

 tin- conidiophores free to produce new conidia. The conidia 

 are capable of immediate -crmimition. and may produce a 

 lateral ^erm-tiibe, which -row-. directly upwards, and .u'ives oil' 

 secondary conidia: or the conidia them-eh,--, -row out into 

 hyphae, capable, as \Voronin proved experimentally, of carrying 

 out infection. Such hyphae pern-irate between the \\alls of 

 adjacent epidermal cells, and uive ri>e to a mycelium which 

 >jii-eads in a d-ntiifu-al direction :md forms the spore- 

 mafi 



This same fun^u-> has also been found on /,'/'/<///</-./" ////// 

 and /'"/-/'.s , t ii,i,l,-ifi>Hii. On AV/////VS/W, accoi-din- to \Vintei-, 

 it causes formation of lar-e ^wellin--. accompunird by i-oii<ider- 

 able deformation of leaf and sii-m. 



T. primulicola (M;i-n.) Knhn. 1 i I'.ritain). Thi- -^mut attacks 

 flowers of /'//////>/</ acaulis, /'. /lirin,i/i-<. /'. ././//</,-, /'. I'm-in 



In cases describe,! \ n (lennany, the bloom- were ^em-rally 

 attacked in the filaments or connective of the -stamens, but a No 

 in the anthers, the ovaries, pi~til, Btigma, and sometimes in the 

 Calyx-tube; while the whole llower-heail was more or i 

 by the black 3DOre-dust. The mycelium perine. 



I: !., I .,./,/ /;,/;/. /'.'./. Ii7>. Kiilm, "ilh- Kntu i. ki 1 

 L -I. l'riiii,-ll,i.iip|, rforach. '.' tell. II 18 



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