288
"Actinomycosis" and Actinobacillosis in Animals
other neighbouring areas and thus start a fresh focus of infection. Not rarely
these coccoid bodies and even mycelial filaments may be disseminated without
the intermediation of phagocytes [M'Fadyean, 1889 ; Delepine, 1890].
The significance of the association, in human actinomycosis, of Bacillus
actinomycetem comitans is not known. The bacillus was first described by
Klinger in 1912 and has subsequently been encountered by others. It is
a small, Gram-negative, pleomorphic, non-motile, non-sporulating, non-encap-
sulated organism and a facultative anaerobe, fatal intravenously to rabbits
and intraperitoneally to guinea-pigs.
The formation of clubs at the periphery of the actino-body is still a matter
of dispute. It is apparent from literature on the subject that clubs are in
many cases, a result of tissue reaction [Meyer and Mayer, 1927]. In actino-
mycosis, however, they are said to represent parts derived from the causal
organism. They are interpreted as degenerated mycelial ends [M'Fadyean,
1889] ; or are explained, by many workers, to be formed by the thickening of
the mycelial capsule [Delepine, 1890 ; Bostroem, 1890]. Others regard them as
organs of fructification giving rise by budding to spores which help to spread
the infection to fresh foci [Crookshank, 1888 ; Gibson, 1934]. Brumpt [1906]
interprets them as the youngest members of the infective agent supplying
nourishment to the older and more centrally situated members, the mycelia.
A brief note on the systematic position of Actinomycetes may be made here.
For want of an accurate knowledge of morpholgy, the claim on this group is
divided between bacteriologists and mycologists. The former base their
arguments mainly on the unusually slender mycelium (0.2 to 1.0 µ) and on the
production of bacilliform asexual reproductive elements (arthrospores) of the
same thickness as the mycelium, and include the organisms under the Schizo¬
mycetes ; whereas, the latter emphasize the formation of spores similar to that
of conidia in the Fungi Imperfecti (Hyphomycetes), and on the markedly low
heat resistance of these spores. Still others regard them as intermediate forms
between bacteria and fungi, or as a parent group from which sprang the fungi
and certain bacteria viz., Mycobacteria and Corynebacteria. Some authors
[Magnusson, 1928 ; Haupt and Zeki, 1933 ; and Klimmer, 1934] have sugges-
ted affinities of A. bovis with the Corynebacteria ; a few others [Grootten,
1934] have put forward a plea in favour of the Mycobacterial nature of Actino-
myces, and as in the case of Mycobacterium tuberculosis evidence of a filtrable
form of A. bovis has been recently put forth by Sartory, Sartory and Meyer
[1933].
The position of Actinobacillus amongst the bacteria is not disputed but
although it is generally considered to belong to the family Actinomycetaceae,
Beaver and Thompson [1930] have suggested its place alongside Pfeifferella.
It will be realised from this paper that the position with regard to " actino-
mycotic " diseases is very unsatisfactory, not only in India but also in other
countries whence, in spite of intensive researches, conflicting statements are
not infrequently reported regarding various aspects of the subject. The pro-
blem is intensified considerably for the veterinarian by the fact that not one