188 Psyche [December 
cultures do not contain pyocyanin, however, as can be shown by 
extracting with chloroform. The coccobacillus grows rapidly on 
gelatine which it liquifies and on gélose (agar) the growth in two 
cases was slightly fluorescent. Streak cultures on gélose (agar) 
spread in a short time all over the surface. On potato the growth 
is feeble and begins to develop only after 48 hours without pro- 
ducing the greenish fluorescent pigment. Caterpillars of Arctia 
caja inoculated in the prolegs with a fine needle dipped in virulent 
blood or in a culture of bouillon die regularly in three days when 
kept at 15 degrees and present an intense multiplication of the 
bacillus in their blood. Inoculated caterpillars die in 12-24 hours 
when they are kept at a temperature of 25 degrees and the blood of 
such individuals appears more virulent than the blood of those 
which die at 15 degrees. If several drops of the culture are intro- 
duced into the pharynx by means of a pipette caterpillars die in 
24 hours at 25 degrees and the coccobacilli invade the blood. 
This fact, that caterpillars can be infected by ingesting the etiologi- 
cal factor, leads the authors to hope for the employment of the 
disease practically. 
Picard and Blane found that brown-tail caterpillars are very 
susceptible to the coccobacillus. The authors inoculated several 
Coleoptera and Hemiptera, but found that the bacterium was 
non-pathogenic to these forms. White rats are also nonsuscepti- 
ble to the intraperitoneal injection of a cubic centimeter of a viru- 
lent culture in bouillon, but the green frog (Hyla arborea) is sus- 
ceptible and dies in 24-48 hours when inoculated in the lymphatic 
spaces. The blood from such a frog is again virulent for cater- 
pillars. 
The above results obtained by Picard and Blane may have been 
correctly interpreted, but they can hardly expect bacteriologists 
to accept them for the following reasons: No account of their 
actual experiments is given; we know nothing about the number 
of caterpillars which were used, and no mention was made of con- 
trols. The absence of accurate controls alone places the article 
among worthless publications. Furthermore, the morphological 
description of their coccobacillus is very superficial and cultural 
features are almost entirely disregarded. They say nothing about 
colonies on nutrient gelatine or agar other than a growth was ob- 
tained on these media. Many other media absolutely essential 
