. Annual report of the Commissioner of Agriculture ... Agriculture -- New York (State). 2o6 Bulletin 132. duced on wilted leaves in a wet season) ; while b and e show the same fun- gus under normal conditions. I have experienced no difficulty in germina- ting the fungus on plates of agar, and in securing pure cultures in tubes of sterile bean stems or of petioles of celery. In this condition the fruiting hy- phae are often ultimately more than a millimeter in length. At first conidia are regularly produced, leaving the accustomed geniculations ; and these couidia vary in length from some excee
. Annual report of the Commissioner of Agriculture ... Agriculture -- New York (State). 2o6 Bulletin 132. duced on wilted leaves in a wet season) ; while b and e show the same fun- gus under normal conditions. I have experienced no difficulty in germina- ting the fungus on plates of agar, and in securing pure cultures in tubes of sterile bean stems or of petioles of celery. In this condition the fruiting hy- phae are often ultimately more than a millimeter in length. At first conidia are regularly produced, leaving the accustomed geniculations ; and these couidia vary in length from some exceedingly short to others measuring 250 /*. After the hyphae have attained considerable length no further conidia are produced ; and, instead, the spore-like branches which arise remain attached, and appear as true branches of fertile hyphae. Figure 49 (Leitz ocular i, objective 4) illustrates the character of growth on bean stems. I neglected to make a photo- graph of a good petri-dish isolation culture until it was badly contaminated with bacteria ; but Fig. 50 serves to show the nature of the growth on agar. The colonies are large, circu- lar, at first olivaceous, and not readily separa- ble from the agar. Later a grayish-white aerial growth of cottony mycelium appears, inter- spersed with which are the long fruiting hyphae. In general, growth in artificial cultures is characteristic, both on agar and on bean stems, differing materially from that of half a dozen Cercospons cultivated diuring the past summer. No perfect stage of this fungus has been secured; but every effort is being made to ascertain if there is an intervening perfect form. As j'et, I have not been able to secure cultxires of Cer- cosp07'ce on hosts closely related to the celerj'.. B. Late Blight of Celery. General Discussion. 49 -Hyphae of the Cercos- pora, when grown on bean stems. At the same time that the early blight was abundant on the Ithaca flats, a differ- ent disease was found in a garden not far dist
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