On endophytic adaptation shown by Erysiphe Graminis DC. under cultural conditions

In recent papers by the author the fact has been pointed out that certain species of the Erysiphaceœ are able, under cultural conditions, to infect their host-plants vigorously when their conidia or ascospores are sown on the cells of the internal tissues exposed by means of a wound, although the fungi in question are confined normally to the external surface of the epidermal cells. The present paper gives the results of investigations carried out in the laboratory of Professor Marshall Ward at Cambridge, with the object of ascertaining the details of growth of the fungus under these abnormal conditions, and of discovering to what extent the hyphæ penetrated into the intercellular spaces of the internal tissues, and whether haustoria (normal or otherwise) were produced by these hyphæ.