Of tuf. ScinNCF of Plant nACTHiuoLOCY 321 



sites, Pseuclomothis cj/nfu'Slns, pkiseoli, and hyacinthi, were ob- 

 served to spread more slowly through the parcnchymatic tissues 

 of their host plants; and their action was compared with that of 

 parasites of more rapid spread within these tissues, to-wit, those 

 of pear blight, brown rot of potato, or soft white rot of hyacinths. 

 Hyperdermic syringes were sometimes used in parenchymatous in- 

 jections, and the exact acidity of each nutrient solution was ascer- 

 tained by titrating it with N/10 Sodium Hydroxide (NaOH) and 

 phenolphthalein." The conclusion was that " Two of these yellow 

 organisms are vessel parasites, their entrance into the plant being 

 favored by the alkaline juice of the ducts. In all three the 

 restraining influence was believed to be, in great part, at least, 

 the acid jiiice of the parenchyma." ^-^ 



" Gelatin Culture Media," '-'' his other paper presented at the 

 1898 meeting of the Society, offered reasons, illustrated by a chart, 

 photographs, paintings, and an accompanying plate showing the 

 " varying behavior " of Pseudomonas campestris in gelatin with 

 dift"erent quantities of caustic soda, why individual workers 

 studying the same organism with these media might reach differ- 

 ent results and conclusions. It was pointed out that 



Working with gelatin of varying grades of acidity and alkalinity, pre- 

 pared according to Fuller's scale, . . . with interpolations and extension of 

 the scale, if necessary, it is possible to obtain curves of growth decidedly 

 different for different species, even those which are morphologically much 

 alike and which behave the same on nutrient agar. 



Gelatin media, he said, should be rendered neutral to phenol- 

 phthalein, and he suggested several techniques usable and effec- 

 tive. He again cited as the " best paper in English " on this subject, 

 " On the Proper Reaction of Nutrient Media for Bacterial Culti- 

 vation," by George W. Fuller, then a resident engineer of Cincin- 

 nati to whom he had sent some of his reprints. 



Fuller was particularly interested in Smith's list of " little-used 

 culture media " ^"° found valuable for differentiating species of 

 bacteria. He promised to use some as time allow^ed. This list, 



^-* Details furnished by Smith in, Wakker's hyacinth germ, Pseudomonas hya- 

 cinthi. Bull. 26, Div. Veg. Phys. and Path., 1901. Preface says that paper was 

 prepared in August, 1897. Also, Bull. 28, The cultural characters of Pseudomonas 

 hyacinthi, Ps. campestris, Ps. phaseoli, and Ps. stewarti etc., 1901. 



"*/1ffzer. Nat. 33(387): 214-215, Mar. 1899. 



^^^Proc. Amer. Assoc. Adv. Set. 47: 412-413. 1898. 



