156 Journal of Agricultural Research [voi. m. no. ^ 



Of 93 nuts from a Frotscher pecan tree, showing rosette over the whole 

 top, 52 germinated. This lot was sent by Mr. C. A. Reed, of the Bureau 

 of Plant Industry, from the Parker orchard, Thomas\ille, Ga. 



Of 25 nuts obtained from resetted branches of Teche, Alley, Stuart, 

 and Van Deman pecans from the orchard of Mr. W. P. BuUard at Albany, 

 Ga., 18 germinated. 



Of 4 nuts from a rosetted branch on an old seedling tree at Marion 

 Farms, near Ocala, Fla., 3 germinated. 



Of a second lot of nuts from Blackshear, Ga., number unknown, taken 

 from a rosetted tree but not from a distinctly diseased branch, 28 germi- 

 nated. 



Out of all the nuts which germinated not a single seedling showed any 

 symptoms of rosette, so that whatever the cause of the disease, it is ap- 

 parently not transmissible through the seed. 



ISOLATION OF MICROORGANISMS AND INOCULATIONS 



To further test the communicability of the disease, several healthy 

 nursery trees at Cairo, Ga., were inoculated with pieces of tissue from a 

 badly diseased branch in August, 1902. The bark was removed from 

 the latter, and bits of the wood scraped up with a sterile scalpel were 

 placed in sterile water. Incisions were then made near the terminal 

 buds of vigorous, healthy branches and bits of the diseased material 

 inserted. This experiment was duplicated in August, 1906, when slices 

 of diseased buds were inserted into the terminal branches of 11 nursery 

 trees. The inoculated trees in both cases remained healthy. 



During the fall of 191 1 a series of attempts was made to isolate any 

 organisms that might be present in various parts of diseased trees. 

 Numerous Petri-dish cultures were made from the inner bark, cambium, 

 wood, and pith of living rosetted twigs and from the pith and inner bark 

 of the living roots ^i inch to 3 inches in diameter. Pieces of the tissue 

 in each case were transferred to beef agar and corn-meal agar. AU 

 these cultures remained sterile. Material for these and the following 

 tests was obtained by the junior author from three orchards at Talla- 

 hassee, Fla., and from specimens received from Sacaton, Ariz. 



With the partly dying tissues, however, many of the cultures gave 

 bacteria and fungi. This was to be expected, since, as is well known, 

 large numbers of saprophytic forms soon obtain entrance to tissues which 

 have died from almost any cause. This is particularly true of tissues 

 which have died from physiological causes, since they are not already 

 infested with fungous or bacterial growth. 



Out of 55 pieces of pith tissue from partly dying twigs, 39 remained 

 sterile, 12 gave colonies of fungi, including an Aspergillus, a Penicillium, 

 and a nonfruiting whitish fungus, and 4 gave as many different types of 

 bacteria. 



