sept. 16,1918 Occurrence of Coccidioidal Granuloma in Cattle 
535 
incubation microscopic examination of the preparations shows the devel¬ 
opment of a few short protoplasmic shoots extending out from the cap¬ 
sules of the spherical forms. These growths very shortly assume the 
character of mycelia, which have a well-defined wall about them, branch 
extensively, and show septa at intervals. A colony of branched inter¬ 
lacing septate mycelial threads from 2 to 8 /x in diameter is formed about 
the capsule of the original sphere in the course of 24 hours. Old cultures, 
particularly those on potato, show an abundance of aerial hyphae bearing 
cylindrical or oval conidia which are surrounded by a doubly contoured 
membrane with a highly refractive and homogeneous protoplasm (PI. 
59. B). 
Wolbach (jj) and MacNeal and Taylor (4) have demonstrated the 
changes that take place in the development of spheres from the mycelial 
filaments. When rabbits are inoculated intravenously with masses of 
filaments and their organs are examined histologically at different stages 
from 24 hours to several weeks, it may be observed that each sphere 
develops from a segment of mycelium. At the end of 24 hours most of 
the filaments have broken up into coarse granules and have largely dis¬ 
appeared; a few, however, remain viable and increase in size, breaking 
up into rectangular segments which continue to enlarge, so that at the 
end of seven days perfect spheres have formed, some showing endospores. 
MacNeal and Taylor (4) have demonstrated in vitro on special media 
and under anaerobic conditions morphologic types, including sporulating 
forms quite similar to the sperical bodies occurring in the tissues. 
CUIyTURAIy CHARACTERS 
Agar. —The rate of development at room temperature is rather slow, no growth 
being visible until after three or four days. Incubated at 37 0 C., colonies are usually 
visible within 24 hours. These first appear somewhat circular in outline, of a silvery 
or grayish color, and very slightly raised above the medium. The mycelia penetrate 
rather deeply into the substratum, giving the colonies so firm an attachment that in 
removing some of the growth it is necessary to dig into the medium with a strong 
platinum wire. After several days the culture assumes a whitish moldy appearance 
caused by the formation of short aerial hyphae. In some tubes these occur in abun¬ 
dance, attaining a length of 2 to 3 mm. and spread around on the inner wall of the 
tubes in profusion, while in others they are much less in evidence. In old cultures 
the medium shows a brownish discoloration, the growth remaining white. As the 
agar dries out, the growth assumes a slightly yellowish-brown tinge. 
Gexatin. —There is a fairly abundant surface growth similar to that on agar. The 
aerial hyphae are not usually so plentiful. In about a week or 10 days a slow 
stratiform liquefaction begins, and eventually the entire mass of medium is liquefied. 
Potato. —The growth is much more luxuriant on this medium than on agar or 
gelatin, the development of aerial hyphae being very marked. The medium becomes 
brownish in old cultures, and the discoloration is imparted to the culture to a certain 
extent. 
Egg medium. —The growth is somewhat similar to that on potato, except that it 
occurs around the margin of the medium and extends on to the sides of the tube for 
the first week or two; later it spreads over the entire surface of the medium. In the 
