PERISPORIEAE. 181 



Species of fungi included in this ur"iip are the cause <>f 

 those Mack, sooty coatings found on leaves tV>-<|iirnted l.y -let-n 

 lly (Aphis) and other leaf-insects. These arc purely epiphytic 

 and saprophytie forms which derive nourishment from the 

 'honey-dew" excivtcd liy the insects. 1 They multiply very 

 rapidly, and soon form dark coatings on the upper >ide of 

 leaves and twigs. Little damage need lie feared, since th>- 

 leaves retain their green colour, and the coating is not 

 to stop access of light. Amongst them are species of 



Milinln, and Apiosporium, as well as the conidial forms 

 Tni-i/l'i, A, ili n niti-ut. 



The modes of reproduction of these forms are exceedingly 

 varied. According to Zopf 2 they form: (1) ascocarps; (2) many- 

 celled large conidia: ( "> ) unicellular, very small conidia : i li 

 isolated and clustered conidiophores ; ( " ) gemmae; (0) luids in 

 a yeast-like manner; while every fragment of a mycelium can 

 produce a new growth. Any of the species may frequent 

 many various plants, and can pass rasily from one host to 

 another. Some of the better-known forms are: 



Capnodium salicinum Mont. < I'.ritain). This occurs on 

 species of willow, poplar, hop. and many oilier plants. 



If it appears early and almndant on hop it may cause 

 considerable damage. (Fn nnti/n rui/nnx is a conidial form). 



C. quercinium 1'ers. on oak. (I'.S. America.) 



C. taxi Sacc. et lloum. on 7 T "<->/\. 



C. foedum Sacc. (spermogonium foTm = Chaetophoma h>l<i). 

 < Mi the leaves of oleander. (U.S. America.) 



The genus Apiosporium forms similar sooty coatin--. 



A. pinophilum Fuck. This covers \\ith a Mack coating 

 wh"le twi'js and leaves of silver tir : the needles however retain 

 their nivi'ii colour completely. (.////////"//" and To/-/'/" arc 

 forms of this.) 



A. rhododendri Fuck.: A. ulmi Fuck.-, and other species. 



Tin- i-iiiiiili.-il form /'///,///,///'<> wliidi |n-oclin'i's ^n-y .-o;it in^s <>n tin- .)!'<.- 

 |il;nit i-. i-i.n~iil.Ti'il anion^ tin- H \ |>ln.my-.-i. 



Species of Meliola aNo produce sooty coatings. 



M. citri Sacc. and M. Penzig"! Sacc. occur on Qi in 



I'. _!'. I >i , iii.ni.iihiin. /.' h( S'mii, n mi I'jl.in . n. Jena (Fi cb< 



/."[t, !!. ( 'iii"lifiil'i'ii.-liif V. FIIHI;II;II. " A'...., acta, \'\. I". Al-n; '/.]>l. 



I ' /' ; I'll!. i -!!-, >'' ' '. /;/;/., III. 



