PRESENT STATUS OF INVESTIGATION OF BEE DISEASES. 45 
broth is quite opaque and whitish looking. A heavy sediment is then present, 
and pellicle formation is just beginning. In ninety-six hours the cloudiness is 
about the same, but there is an increase of sediment, and the pellicle is thin and 
membranous. Reaction of media after ten days’ growth, +4.04. The bacilli 
average 5 uw in length. 
Gelatine plates.—At 22° C., in twenty-four to thirty-six hours, the colonies are 
small, round, oval, or lozenge-shaped, with peculiar projections or shoots from 
one end of the colony, giving it a pear-shaped or tadpole-like appearance, 
according to the amount of development of the projection. In many cases 
several of these outgrowths occur from different portions of the colony. By 
placing a cover glass on the surface of the gelatine and using objective 7, the 
bacilli may be seen moving around and around the colony and to and fro along 
the projections. At the end of forty-eight hours the colonies are larger. Fine 
processes or projections are shooting out into the gelatine in all directions, 
forming peculiar figures in circles or club-like forms. ‘It is impossible,’ says 
Cheyne, “to give a proper idea of the appearance of the growth. The forms 
assumed are the most beautiful shaped I have ever seen; but they are very 
numerous, always retaining the tendency to form curves and circles.’ After a 
time the gelatine is liquefied and the beautiful appearance of the colony is 
destroyed by the liquefaction of the gelatin. 
These peculiar shaped colonies are most typical when the germ is taken 
from the diseased larvee. After prolonged cultivation on various kinds of media, 
there is a tendency for the colonies to become round, and the peculiar branech- 
ing forms are not seen in such numbers. The composition of the gelatine 
also seems to make a difference in the appearance of the colonies. In gelatine 
containing 12 per cent gelatine the processes are not so long. The same effect 
may be brought about by using more peptone in the composition of the media. 
Gelatine tubes.——In stick cultures at 20° C. growth occurs all along the line 
of puncture. On the surface delicate branching or ramifying growth occurs in 
three days. ‘These outgrowths soon run together and the gelatine is liquefied, 
first around the line of puncture, and in five days extends over the whole 
surface. The growth in the depth of the gelatine occurs as a whitish streak 
all along the needle track, and from this numerous shoots and growths branch 
out into the gelatine in all directions, giving a haziness to the appearance of 
the gelatine, which then begins to liquefy. If the inoculation is a heavy one, 
the shoots are coarse and may have club-shaped extremities, and from these 
swollen ends fresh shoots may start. Cheyne obtained the most chuaracter- 
istic growth in gelatine containing 3 per cent of peptone as well as 10 per cent 
gelatine. The whole tube is liquefied in from two to four weeks’ growth. The 
liquid becomes yellowish in color and gives off a peculiar odor. Klamann 
states that in gelatin acidified with lactic acid the growth is slow and long 
threads are formed. 
Gelatine streak cultures.—In gelatine streak cultures the appearance is very 
similar to what one sees in stick cultures. The bacilli first grow along the line 
of inoculation, and then throw out shoots into the surrounding gelatine, pro- 
ducing the appearance noted in the stick culture. The bacilli move to and fro 
along the channels of liquefied gelatine. 
Agar plates.—On agar plates at 37° C. the colonies at the end of eight hours 
are small and burr-like, with spines protruding in all directions, giving the 
colony the appearance of a sea urchin. In some cases the projections are 
from one side or end. At the end of twelve hours the colonies have well- 
defined projections, visible to the naked eye. The colonies in the depths of 
the agar are more spiny, the processes being much shorter. On agar plates 
