1248 MANUAL OF DETERMINATIVE BACTERIOLOGY 



FAMILY III. ERRONACEAE FAM. NOV. 



Viruses of the Encephalitis Group, inducing diseases mainly characterized by ef- 

 fects on nerve tissues. 



Key to the genera of family Erronaceae. 



I. Viruses of the Typical Encephalitis Group. 



Genus I. Erro, p. 1248. 

 II. Viruses of the Poliomyelitis Group. 

 Genus II. Legio, p. 1257. 

 III. Viruses of the Rabies Group. 



Genus III. Formido, p. 1263. 



Genus I. Erro gen. nov. 



Viruses of the Typical Encephalitis Group, inducing diseases mainly characterized 

 by injuries to cells of the brain. Vectors of some known to be ticks ; dipterous insects 

 may also transmit. Generic name from Latin erro, a vagrant. 



The type species is Erro scoticus spec. nov. 



Key to the species of genus Erro. 



I. Affecting sheep principally, but also man. 



1. Erro scoticus. 

 II. Affecting man principally. 



2. Erro silvesiris. 



3. Erro incognitus. 



4. Erro japonicxis. 



5. Erro nili. 



6. Erro scelestus, 



III. Affecting horse principally, but also man. 



7. Erro equinus. 



IV. Affecting horse, cow, sheep. 



8. Erro bornensis. 



1. Erro scoticus spec. no;.'. FromLatin lion, champingof jaws; prostration, coma, 



Scoticus, Scottish. death. In man, encephalitis with 



Common name: Louping-ill virus. prompt and complete recovery accom- 



Hosts: BOVIDAE—Ovis aries L., panied by formation of specific neutraliz- 



sheep. HOM I N I DAE— Homo sapiens ing antibodies. In mouse, experimen- 



L., man. Experimentally, also mouse, tally, diffuse encephalomyelitis with mild 



rat (subclinical infection), chick embryo meningeal involvement; following intra- 



(discrete primary lesions on chorioallan- cerebral inoculation, fine rhythmical 



toic membrane), Macacus rhesus, horse, tremor involving neck, nose, and ears, 



cow, pig. unsteadiness, muscle spasms, respiratory 



Insusceptible species : Guinea pig, distress, sometimes clonic and rarely 



rabbit. tonic convulsions; hind limb paralysis, 



Geographical distribution : Scotland, dribbling of urine, cessation of spontane- 



northern England. ous limb movements, death; in mouse 



Induced disease: In sheep, encephalitis inoculated intraperitoneally, virus usu- 



characterized by dullness followed by ally enters central nervous system by 



incoordination of movement, frequently way of the olfactory mucosa and olfactory 



with tremors chiefly of the head; saliva- bulb, occasionally by trauma at points of 



