184 THE JOURNAL OF BOTANY 
patches—thirty or forty yards square—of young plants of gris 
pratense, on whi Bee n Oidium was so ee ful ae the 
ane 
dispersa Krikss., one of the Uredinee (see Marshall Ward in Sarat, 
Mycolog. i. p. 132 (1903) ). 
II. Mycornagous Larv® FEEDING oN Conzpra OF on haedrgad 
aa on the followin reece with he Oidium of E. ara mints 
on Poa pratensis, Avena sativa, Lotion italicum, Bromus ster ilis, B, 
commutatus, B. arduennensis, B, interruptus, B. hor ‘deaceus, Festuca 
elatior var. pratensis, Milium effusum, and Agropyron repens ; ment the 
Oidium of EF. Cichoracearum on Plantago major, He orgee d 
Arctium intermedium ; with the Oidium of E. Polygoni on aes 
sylvestris, Heracleum Sphondylium, Trifolium procumbens, T. e, 
T’. incarnatum, Ranunculus repens, Sisymbrium UT ae and Ono- 
brychis sativa; with the Oidiwn of EF. Galeopsidis on Lamium album, 
Stachys silvatica, Ballota nigra, and Marrubium Roischyt with the 
Oidium of Spharotheca Humuli on Humulus Lupulus and Potentilia 
reptans, and with the nes of S. Humuli var. fuliginea on Leon- 
todon Taraxacum and Plantago lanceolata; with the Oidiuwm of S. 
mors-uve on fibes Grossularia ; with the Oidiwm of S. pannosa on 
— roses ; with the Oidium of Uncinula Aceris on Acer cam- 
pestre; and with the Oidium of some undetermined species on Pyrus 
Malus, Cuicus lanceolatus, Myosotis arvensis, praeee arvensis, Ver- 
bascum Thapsus, Geranium malt, and Calendula 
were extremely numerous on the mil- 
dewed parts of the hE ee: as throughout the larval RE 
they never cease feeding voraciously on “the conidia, they must in 
some measure tend to dec ecrease the ne at wae the fungus 
of conidia. In all the cases kept r Me aan: Saaiiy. the 
fungus itself on the plant St able to continue 
apparently unchecked. As instances of the prevalence of these 
0 
some districts, 1 may mention the two following cases. 
Ten pieces of shoots of ‘the gooseberry, about 6 in. long, severely 
attacked by Spherotheca mors-uve, were picked at random from a 
garden in Ireland, and sent = me at Kew by post. When these 
oots were examined, over seventy larve were found feeding on 
the conidia. On two little mildewed apple-twigs, about 5 in. long, 
and each bearing about six leaves, also picked at random in Ireland, 
and sent through the post, no less than thirty-one of these larvee 
were found feeding on the fungus when it arrived at Kew 
