140 Wisconsin Academy of Sciences, Arts, and Letters. 
Conidia from Poa pratensis will infect P. pratensis, P. an¬ 
nua* and P. nemoralis* but not Festuca elatior var pratensis y 
F. arundinacea, F. heterophylla, Lolium perenne, L. temulent- 
um, Dactylis glomerata, Phleum pratense, Alopecurus pratensis r 
Avena sativa, Hordeum vulgare, Triticum vulgare, Secale 
cereale, nor Agropyron repens. 
Conidia from Dactylis glomerata will infect D. glomerata but 
not Avena sativa, Secale cereale, Triticum vulgare, Lolium 
temulentum, Hordeum vulgare, nor Agropyron repens. 
2. Conidia of Sphaerotheca humuli from Potentilla reptans 
will infect P. reptans but not Alchemilla vulgaris, A. arvensis r 
Fragaria sp. (cult), Spiraea TJlmaria, Agrimonia Eupatoria, 
nor Potesium officinale. 
3. Conidia of Sphaerotheca humuli var. fuliginea from Tar¬ 
axacum officinale will infect T. officinale but not Plantago 
media, P. lanceolata, nor Fragaria sp. (cult.) 
Conidia from Plan tag o lanceolata will infect P. lanceolata but 
not P. major nor Taraxacum officinale. 
4. Conidia of Erysiphe cichoracearum DC. from Plantago 
major will infect P. major, P. media, but not P. lanceolata, 
Galium Aparine nor Eupatorium cannabinum. 
5. Conidia of Erysiphe galeopsiclis DC. from Ballota nigra 
will infect B. nigra, but not Salvia verticillata nor Leonurus 
Cardiaca. 
Salmon (11) also made some infection experiments with asco- 
spores from Hordeum vulgare during the spring of 1903. The 
ascospores infected Hordeum vulgare, H. zeocriton, and H. trifur- 
catum, but not Triticum vulgare, Avena saliva, Secale cereale, 
H. maritimum, H. secalinum■, H. jubatum, nor H. bulOosum. 
The ascospores corresponded in their infecting powers to the 
conidia from the same host except in the case of H. jubatum. 
Marchal says that the conidia from H. vulgare will infect H. 
jubatum. Salmon states, on the contrary, that he lias not been 
able to infect H. jubatum with conidia from H. vulgare. How¬ 
ever, so far as the infecting power of the ascospores alone is 
concerned, one experiment is not sufficient to determine. 
As a result of the investigations summarized above, it may be 
* “Sub-infection.” 
