INFECTION-POWERS OF ACOSPORES IN ERYSIPHACEE 207 
fungus was beginning to spread to the controls. Of the inoculated 
leaves of H. trifurcatum two bore small powdery Oidiwn patches ; 
the ie were all still free. No trace of infection resulted on 
H, bulbos 
Summary oF INFECTION-EXPERIMENTS WITH THE ASCOSPORES OF 
E. Graminis on HorpEUM VULGARE. 
ri aaa crea ™m 
| | obs 
} | s#ao0n, 
' | Age of |No. of |\No. of |S BRS . 
Exper.| Date, Species used as plants | leaves | leaves |S 3 3 g e 
No. 1903. Host. | inocu- jinocu-|  in- Reese 
lated. | lated. fected.) 2.9 5-3 5 
3°E woe 
mu.8 
: a one 
la | March 19| Avena sativa ...... | Sdays| 38 0 | 3 days 
4¢ Pestgay 3 See Ne ve ees i ots 3 0 ass 
7b | April 3 errr Tae i eae 3 0 fee 
lle 5 17 a eerie 14) 5, 3 0 6. 
12¢ Se it, einai Gare yok: ee Ve eee 3 0 6%), 
lb | March 19] Tr iiiewin vulgare | 8 ,, 8 0 as 
4a cial pe nei ced aoe 3 G-5 |th 
Be .| April --1 HE SE oleate is aie 3 0 sane 
le | March 19| Secale cereale ...... Si 4 0 Biss 
3b ee Soe ees ho a 2 0 Gu 
5b | April 1 ign eee 3 aoe 3 0 ae 
6b ES Dy, eG ee a2 Oy 3 0 G5 
3a | March 31 Hordeum pice eae Ss 3 8: ,; 
4b pee atte T ee, See 1g, 3 3 4 ,, 
5a | April 1 pe aiserg push cues yee 3 3 ay, 
6a Sate WPM Vee 3 ie 
7a is 3 FR as an i ene 4 4 (foe 
10a we ae Pi us eT i he age 6 6 ay 
lla Wwreay 7 eee ms 3 te ee ee 
12a yesAlt pee oa ae 145 y, 3 ae ee 
Weis 116 ia sai 925; 3 Gales 
14b wii a eee 6% 3 Rohebey 
ib. «4.20 og Se 7 3 ae Bee 
Beet On a etait if. 3 ee eee 
10b | April 16| H. maritimum ....20 4, 3 A a 
18¢ + 1 eevee 22, ” 3 0 | 7 ” 
lib Oaaae Yio igs 3 secalenum id Fa yy 4! Jae 3 a Os 
Hebe os yi 48 . Weer Ee ee ena 
bt 18 ge Bila Aeke i, op Oe Pio 
lba oO ional au Pb Oia 
l4a wea. WO A. jubatum joctabie- | 20 yy Bert 8 6 5, 
l4c | ,, 29| H. bulbosum ...... LT wm fo BO) Bae 
l6¢g May 7 seceuet ae ‘ 3 | 0 | 5 bad 
16b % ct Ge Beocriton fateh uv yt Ss | 1 | a. 
16e | ,,  7| H. trifurcatum ...| 9 3 S| 2» 
experiments above - tabulated seem to give conclusive evi- 
dango thet Ut Graminis comprises in its ascigerous stage § ined 
— forms.” Hitherto that sp of p which 
