FILTERABLE VIRUSES 635 
the blood, spinal fluid and emulsions of the central ner^•ous system 
from cases or autopsies, were found to be infecti\'e for rabbits and 
monkeys. Emulsions from the brains of infected animals reproduced 
the disease in other animals, after the passage of the material through 
Berkefeld filters. Thalhimer' has repeated these experiments in detail, 
and seems to have confirmed them both with reference to passage of the 
virus through a series of animals, and with respect to cultivation of 
the globoid bodies in ascitic fluid tissue medium. The virus of Strauss 
and Loewe is reminiscent of the filter-passing globoid body found in 
poliomyelitis. It is interesting to note that cultivations in the ascitic 
fluid glucose-agar medium, which give positive growths with the cocci 
described by Kosenow, IVIathers and others, in poliomyelitis, failed to 
show growth when applied to the study of infective material from cases 
•of lethargic encephalitis.- The work of Loewe and Strauss,^ and of 
Thalhimer.^ has been corroborated in part by Levaditi and Harvier,^ 
and others, and the filterable globoid body described by them is thought 
by many to be the etiological agent of lethargic encephalitis for the fol- 
lowing reasons: 
1. The organism has been obtained from lesions and fluids of 
undoubted cases of lethargic encephalitis. 
2. The organism has been cultivated for several generations outside 
the body in artificial media. 
3. Upon injection into suitable animals, the descendants (sixth 
transfer) of the organisms obtained from human cases, induced the 
characteristic symptoms and lesions of the disease. 
4. Cultivations from the lesions of artificially infected animals are 
successful— the organism can be passed through suitable filters and 
grown in suitable cultural media. 
5. Berkefeld filtrates of the brains of infected animals induce 
characteristic lesions and symptoms when injected into other suitable 
experimental animals. 
6. The similarity of the filterable organism cultivated from cases 
of lethargic encephalitis, possessing in common many points of resem- 
blance with the virus of poliomyelitis, strengthens the probability 
that these respective minute organisms, and not larger coccal forms, 
are the respective incitants of poliomyelitis and lethargic encephalitis. 
Much recent work, however, has throA\Ti doubt upon the causative 
relation of these globoid bodies to the disease, and its etiology is still 
obscure. 
Foot and Mouth Disease.'^— Foot and Mouth disease is an acute 
highly infectious exanthematous disease which attacks cloven-footed 
1 Arch. Neurol, and Psychiat., 1921, 5, 113. 
^ House (Jour. Am. Med. Assn., 1920, 74, 884) has desfribcd a grecn-culor-producing 
coccus from a case of encephalitis. 
3 Loc. cit. ^ Loc. cit. 
5 Compt. rend. Soc. de biol., 1920, 83, .354. 
^ For an excellent discussion of various aspects of the disease, see the Cornell Vet., 
February, 19 It's, Foot and Mouth Disease Number. 
