1897.] The Bacterial Diseases of Plants: 131 
lying in the warm, wet earth. This seems to be established 
by Dr. Kramer’s own experiments (see last paragraph under 
(IT) 1 (C.). He has shown clearly that the species in question 
will produce wet rot, but not that many other species would 
not also produce it under like conditions. A much severer 
test of the parasitic nature of this organism would be the 
inoculation of the growing leaves and stems of the potato under 
normal conditions of temperature and moisture, simply by. 
means of needle pricks. Under these conditions it is possible 
the organism might be shorn of much of its power or refuse to 
grow altogether. The determination of this point offers an 
interesting field of experiment for some one. 
2. Morphology : 
(1) Shape, size, ete.—This organism is described as a Bacillus. 
It forms rods 2.5-4.0 x 0.7-0.8 ». On gelatine and agar plates 
chains are common, as are also apparently non-septate threads 
which frequently reach a length of 16 ».and more. In nutrient 
fluids and on potato the rods are for the most part shorter, 7. e. 
1.5 to 2.0 ». long. The rods are rounded at the ends. The 
threads taper off and are wavy. Spindle-shaped organisms 
could not be found. 
(2) Capsule—No mention of any capsule. 
(3) Flagella.—The rods are actively motile. No mention of 
flagella. 
(4) Spores.—Thicker, ellipsoidal forms occur in old cultures. 
These are 1.83 x 2.0. They have a strongly developed mem- 
brane and their plasma becomes differentiated and more 
strongly refractive. This is the commencement of spore 
formation. The mature spores fill the whole interior of the 
cell. 
(5) Zoogloea.—No mention of zooglæa. 
(6) Involution forms—No mention of any distorted forms. 
3. Biology : by 
(1) Stains—The vegetative rods take all the common anilin 
stains, and the spores may be colored very prettily by Neisser’s 
method. : 
(2) Gelatin.—On plates of nutrient gelatin the organism forms 
dirty-white colonies, around the periphery of which the gelatin 
10 
