The fructifications of a hitherto undescribed Endogone sp. have been found in organic connexion with mycorrhizal strawberry roots grown in pots in a greenhouse. By inoculating sterilized soil with these fructifications and with spores excised from them it has been possible to produce typical vesicular-arbuscular infections in strawberry, apple, and a number of other plants. These inoculation experiments constitute the first record of the establishment of endotrophic mycorrhizal infection in plants raised under aseptic conditions.