FAMILY BORRELIOTACEAE 



1243 



the normal histiocj^te, but virus in the 

 affected fowl is not confined to the sar- 

 coma, being widespread in the body in 

 spleen, liver, muscle, brain, etc. In the 

 chick embryo, serial passage is feasible on 

 the egg membrane, in which focal lesions 

 involve only ectodermal tissue. 



Transmission : By injection of affected 

 fowl cells or filtrates. Certain trans- 

 missible tar-induced sarcomas, not in- 

 fecting by filtrates, nevertheless induce 

 the formation of antibodies capable of 

 neutralizing this virus. An inhibitor of 

 the virus extracted from tumors appears 

 to be a protein, inactivated at 65° C, but 

 not at 55° C, in 30 minutes and destroyed 

 by trj'psin in 3 to 5 hours at pH 8. Oleic 

 acid also may act as an inhibitor. No 

 spontaneous transmission in chickens 

 kept together. 



Serological relationships : Particles sedi- 

 mented by centrifugal force 20,000 to 

 30,000 times gravity are specifically ag- 

 glutinated by sera of fowls bearing 

 corresponding tumor. At least one anti- 

 gen in tumors of hen and duck not in 

 healthy birds ; this one fixes complement 

 and gives cross reactions with Rous, Mill 

 Hill 2, Fujinami, and RFD2 tumors. 

 Virus injected into goats produces two 

 antibodies but only one if previously 

 heated; the antibody to the heat-stable 

 constituent requires complement to neu- 

 tralize virus ; the only antibody produced 

 in ducks does not require complement to 

 neutralize. 



Thermal inactivation : At or below 54° 

 C in 20 minutes. 



Filterability : Passes Berkefeld V and 

 no. 5 (medium) filters. 



Other properties: Particle size esti- 

 mated as about 100 millimicrons (but 

 some say 50 or even 15 millimicrons) in 

 diameter by filtration through graded 

 membranes, about 70 millimicrons 

 (molecular weight 140,000,000) by ultra- 

 cent rifugat ion. Contains 8.5 to 9.0 per 

 cent nitrogen, 1.5 per cent phosphorus. 

 Protein tests positive. Feulgen reaction 

 for thymonucleic acid absent ; 10 to 15 

 per cent of the protein maj^ be nucleic 



acid, probably of ribose type. PeBtose 

 present . Virus believed to be of globulin 

 nature or attached to globulin particles 

 (Lewis and Mendelsohn, Am. Jour. Hyg., 

 12, 1930, 686-689). Viable indefinitely in 

 dried spleen as in dried sarcoma tissues. 



Strains : Several strains have been 

 studied in addition to the original Rous 

 sarcoma no. 1 strain; immunological rela- 

 tionships have been shown between the 

 original strain, the des Ligneris sarcoma 

 strain, the Fujinami sarcoma strain, the 

 fibrosarcoma MHl and endothelioma 

 MH2 strains; other isolates also have 

 shown serological interrelationships. 



Literature : Amies, Jour. Path, and 

 Bact., 44, 1937, 141-166; Amies et al.. Am 

 Jour. Cancer, 35, 1939, 72-79 ; Andrewes 

 Jour. Path, and Bact., 34, 1931, 91-107 

 35, 1932, 407-413 ; 37, 1933, 17-25, 27-44 

 43, 1936, 23-33; Claude, Jour. Exp. Med. 

 66, 1937, 59-72; Science, 87, 1938, 467-468 

 90, 1939, 213-214; Am. Jour. Cancer, 37 

 1939, 59-63; Claude and Rothen, Jour 

 Exp. Med., 71, 1940, 619-633; Dmochow- 

 ski and Knox, Brit. Jour. Exp. Path., 20, 

 1939, 466-472; Elford and Andrewes, 

 ibid., 16, 1935, 61-66; Gye and Purdy, 

 Jour. Path, and Bact., 34, 1931, 116-117 

 (Abst.) ; Haddow, ibid., 37, 1933, 149-155 ; 

 Helmer, Jour. E.xp. Med., 64, 1936, 333- 

 338; Keogh, Brit. Jour. Exp. Path., 19, 

 1938, 1-9; Ledingham and Gye, Lancet, 

 228, 1935 {1), 376-377; Lewis and Men- 

 delsohn, Am. Jour. Hyg., 12, 1930, 686- 

 689; des Ligneris, Am. Jour. Cancer, 16, 

 1932, 307-321 ; Mcintosh, Jour. Path, and 

 Bact., 41, 1935, 215-217; Mellanby, Jour. 

 Path, and Bact., 46, 1938, 447-460; 47, 

 1938, 47-64; Mendelsohn et al., Am. 

 Jour. Hyg., 14, 1931, 421-425; Purdy, 

 Brit. Jour. Exp. Path., 13, 1932, 473-479; 

 Rous, Jour. Exp. Med., 13, 1911, 397-411. 



6. Molitor gingivalis spec. nov. From 

 Latin gingiva, gum. 



Common name : Rabbit oral -papilloma- 

 tosis virus. 



Hosts: LEPORIDAE—Oryctolagm 

 cuniculus (L.), domestic rabbit. Ex- 

 perimentally, also Lepus americanus 



