PLASM' il' 



131 



PI. viburni, Peck. On Vilirn>nn (I'.S. America). 

 PI. densa (Kabh.). <)n Scrophularineae (Britain). 

 PI. ribicola (S<-]iri,,-t.). < >n ///'/.< ////<////// (I'.S. America). 

 PI. epilobii (]!al>h.). On A*^"'/,, /,/,/, y,.//".<//v. an<l A', //-//v/y., //-/<. 

 PI. obducens (Schroet.). On cotyledons of Imp"ti>-i:.-i (I'.S. Ann-rica). 

 PI. geranii (Peck.). On Geraniums in Anifi-i<-a. 



PI. Halstedii, Uerl. and de Toni. On >Y/y,/, /,/<, A', /,//,/ /./, Reliant} 

 ami many other American Compositae. 



Sclerospora. 



Mycelium intercellular in living plant-tissues, and deriving 

 nourishment by means of hausturia. The conidiophores are 

 tliick, short, and divide at their apices into short broad branches, 

 from each of which a single conidium is abjointed. The cunidia 

 in germinating discharge swarming cells. One oospore is funned 

 in each oogonium. 



Sclerospora graminicola (Sacc.) lives in several species of 

 ,s'. taria ( I'.S. America). 



Bremia. 



Myci'linm intercellular in higher plants and nourished by 

 little button-like haustoria. The conidiophores are branched, 

 and at their apical ends 

 become swollen in a cbar- 



teristic manner, so as to 

 I-.--. -mble a hand held cup- 

 like with the fingers project- 

 ing separately upwards, like 



tin- tflltaelrs of Ifi/ili'it. The 



'iiiidia are abjoininl singly 

 from the tentacle-like pro- 

 and ji'iminati-, emil- 

 tiirj a germ-tube through ;i 

 di-tinitf thin .-pui in their 



a. i lospore Mii-iu;ite 



Ay in oogonia. 



Bremia lactucae. Reg. 

 (Pen wspora ganglioniformis 



Berk. 1 ) ( Hrilain and U.S. Ami'i-ira). The rirldy-liranrli.-d c 

 l)lioiv-, appear -in-ly mi attacked parl- of plants. Th:-; fungus 



1 ( 'i.i-ini, i '"in/*', rend., I ^7 S . 



i 



