DESCRIPTION OF BACILLUS ALVEI. 31 
the first 28 hours. This led him to conclude that the time when 
spores are produced might depend upon the amount of bouillon used 
and the number of bacilli present. This caused him to devise a sec- 
ond method. The second method involved the use of a flask of sterile 
bouillon, which was inoculated with the vegetative form only of the 
bacillus. This flask was placed in the incubator for two or three 
hours that the organisms might diffuse equally throughout. The 
flask was then shaken, and by means of a syringe gauged on the 
piston equal quantities of the medium and bacilli were taken. Ina 
series of preparations thus obtained and kept at 36° C. the earliest 
appearance of spore formation was evident in 41 hours. 
Cheyne records the fact that the swelling in the rod which takes 
place is usually near the center, but sometimes nearer an end. ‘This 
swelling increases in size at its center and gradually fails to take the 
stain. The capsule of the spore, he states, is apparently formed 
within the rod and is not the outer part of the rod. In three or four 
hours after the spore was formed it was either entirely free from the 
rod, or the rod still inclosed the spore, but was almost invisible. 
Having thus studied somewhat carefully the morphology (size, 
form, and structure) of Bacillus alver, Cheyne took up the further 
study of the species to determine its cultural characters, stating at 
this point, very properly, that the microscope is of little use in deter- 
mining the relation of the bacillus to foul brood. The technique 
which he used in making cultures is very similar to that used in gen- 
eral bacteriological work at the present time, the chief difference 
being that now additional differential media are used. 
DESCRIPTION OF BACILLUS ALVEI. 
The following is an abridged description of Bacillus alvet as given 
by Cheyne: : 
Occurrence.—\solated from larve said by Cheshire to be affected 
with foul brood. As far as is at present known it has not been found 
elsewhere. 
Gelatin plates—Gelatin plates were inoculated by stroking the 
solidified medium with the needle. From small masses of growth, 
which soon form along this line of inoculation, bacilli in Indian file, 
or two or three side by side, grow out into the gelatin. These out- 
growths are not straight, but tend to curve, and at a short distance 
_ from the track of the needle they grow round so as to form a circle. 
From such a circle other fresh circles may be formed. The growth 
about this line increases, filling up the center of the circle. These 
circular growths increase and may join one another, forming a curved 
anastomosis. The gelatin in the immediate vicinity of the growth 
