THE CINNAMON FUNGUS. 37 



infected flies, and, both wet iiud dry, were dusted with ji mixtui-e of 

 infected flies and Hour a})plied with a blowgiin. No fungus developed 

 on checks kept on these experiments. 



THE CINNAMON FUNGUS. 



{Vcrticillium hderocladum Pcnz.) 



History.— The cinnamon fun<^is ( Verticillium Tieterocladum) was first 

 described by O. Penziiij in 1SS2 attacking the soft scale (Leeanium) 

 (\)ccus hesperuliiDi Jj. on lemon leaves in Italy. In 1905 Dr. E. H. 

 Sellards, then (Mitomologist of the Florida Experiment Station, found 

 it growing on Alo/rodcs citrl at Palmetto, Fla., on leaves also bearing 

 numerous pustules of the brown fungus. As no fruiting bodies of the 

 latter hail ever been found, for several years it was thought possible 

 that it might be the s])ore-bearing stage of the brown fungus. How- 

 ever, it has since been proved distinct by Prof. II. S. Fawcctt, who has 

 referred it to Penzig's species, and in 1908 published the results of his 

 studies begun in 1905, giving an account of its history, its description, 

 and biological notes. 



Description. — The pustules of this fungus are brownish-gi'ay or 

 cinnamon colored and are surrounded by a whitish feltlike growth 

 spreading out over the leaf for a short distance 'around the pustule. 

 In general appearance, when not gi-owing luxuriantly, tliis VerticiUium 

 superficially resembles the brown fungus. The following technical 

 description is cpioted from Prof. Fawcett: ^ 



The i)ustulcs, which an- cinnamon colored, are powdery on the surface. Under 

 the hand lens they appear linishlike in form, bristling with hjqihiT}. From the edge 

 of the pustules there grows out a creeping layer of white, delicate, interwoven hj^^hae. 

 From these colorless lij^iha?, as well as from tlie top of the pustules, there arise upright 

 conidiophores. These may have either a simple series of whorls, two to four branches 

 in each, or the branches of the whorls may again be whorled. The conidia are borne 

 on the ends of the ultimate branches. The conidiophores are quite delicate, slender, 

 hyaline, 150 to 240 microns by 3 to 4 microns, several times septate. The conidia 

 are oblong, hyaline, 4 to 6 micoms long by 1.5 to 2.5 thick. The main body of the 

 cinnamon-colored stroma when mature becomes powdery in appearance, and under 

 the microscope it is found that the hyphae have ])roken up into short pieces irreg- 

 ular in shape and length with rounded ends, some of them quite closely imi- 

 tating spores. These have thicker walls than the conidia, and probably act ^s repro- 

 ductive bodies in carrying the fungus through a period of dry weather. 



The resemblance to the brown fungus mentioned above is jnost 

 striking when the pustules are very scattering and only partially 

 developed. However, wlien very abundant, as showni in Plate VIII, 

 tlie similarity between the two fungi disappears. Leaves have been 

 found in which the underside was entirely concealed beneatli the 

 feltlike mycelial growth surroimding tlie pustules. Tliis running 

 together of the mycelial growths of the several pustules is shown in 



I Special Studies No. 1, Univ. of Florida, p. 23, 1908. 



