354 



SCIENCE 



[N. S. Vol. XLII. No. 1080 



Attenuated B. coU is more readily shown, also lished, would open the door to need for important 

 less interference from overgrowths in the five-per- revision of our present ideas in regard to amoebic 

 cent, bile media. dysentery. 



Infection and ImTnunity 

 Under the supervision of J. A. Kolmer 



The Parasite of Oral Endamosbiasis. Endamceba 



gingivalis (Gros) : Allen J. Smith, M.D., and 



M. T. Baerett, D.D.S. 



The authors present a detailed comparison of 

 the amoebiform organisms which have been an- 

 nounced as discovered in the human mouth and re- 

 lated parts, including the amoebae of Gros (1849), 

 of Steinberg (1862), of Grassi (1879), of Flexner 

 (1892), Kartulis (1893), of Prowazek (1904) and 

 of Verdun and Bruyant (1907). They conclude 

 that of these all save the last are really specifically 

 identical and therefore propose as the proper 

 nomenclature for this organism Endamoeba gingi- 

 valis (Gros) with synonyms: Amiba buocalis 

 Steinberg, 1862; Amoeba dentalis Grassi, 1879; 

 Entamceba kartuUsi Doflein (Amoeba m/ixilaris 

 Kartulis, 1907) ; and Entamoeba buccalis Prow- 

 azek, 1904. The organism is an amoeba which 

 ordinarily is of 30 or 35 mieromillimeters in diam- 

 eter in the resting stage, has a fairly differentiated 

 eetosareous periphery, a granular endosarc, full of 

 nutrition vacuoles in which are found bacteria, rem- 

 nants of leucocytic nuclei and red blood cells or 

 their detritus. There is no contractile vacuole. 

 The nucleus is small, usually central or subeentral, 

 but occasionally exeentric ; is seen with difficulty if 

 at all in the unstained specimen; is poor in chro- 

 matin and vesicular in appearance, with small cen- 

 tral ' ' binnenkorper ' ' and a delicate but irregularly 

 thickened chromatic membrane. The pseudopodia 

 are ordinarily single or few, broadly lobose to long 

 and digitate; cellular and pseudopodial motility 

 active but variable; reproduction surely by binary 

 division and by gemmation; persisting cysts 

 formed, but no reproduction cysts as yet observed. 

 Habitat in the pus of pyorrhea pockets, on the 

 neighboring mucous and dental surfaces, in the 

 tonsils, in the abscesses of the jaw, etc. 



The writers urge their inability to distinguish 

 morphologically between Endamoeba gingivalis 

 (Gros) and Endamoeba histolytica Sehaudinn. 

 While stating this view of morphological indistin- 

 guishability, the writers are unwilling to declare 

 general biological identity, although they suspect 

 it; and acknowledge that such identity, if estab- 



The Production and Detection of Specific Fer- 

 ments for the Typhoid-coli Group: Geoege H. 

 Smith. 

 The results of the application of the Abderhalden 



reaction to the investigation of three important 



problems were presented, namely: 



1. To what degree does the property of specific- 

 ity extend among ferments produced in the body 

 through resistance to infective agents? 



2. Which method of administration' — intra- 

 venous, intraperitoneal, or subcutaneous — is the 

 most effective for immunization? 



3. Is there any difference in rapidity of action 

 between living bacteria, killed bacteria and killed 

 sensitized bacteria when used for immunization? 



As regards specificity of ferments, reference is 

 made to previous work with Staphyloccus, Strepto- 

 coccus, Pneumococcus, Micrococcus catarrhalis and 

 B. infiuen-zw in which a complete specificity of fer- 

 ments was demonstrated. In the present instance 

 rabbits were immunized against B. coli communis, 

 B. coli communior, paratyphoid bacillus A, paraty- 

 phoid bacillus B, and two strains of typhoid ba- 

 cillus known as the Hopkins and Eawlings strains. 

 The results of these experiments would indicate that 

 ferments produced as a result of injections with 

 the bacteria employed are highly specific. 



The experiments with the different methods of 

 injection, and with living, killed unsensitized and 

 killed sensitized bacteria were conducted as fol- 

 lows: 



The typhoid bacillus (Rawlings strain) was the 

 organism employed. Doses of 50 million were 

 given intravenously, intraperitoneally, and sub- 

 cutaneously. The animals were bled at stated in- 

 tervals and the serums tested by the Abderhalden 

 method for specific ferments. 



From this work it appears that the intravenous 

 method of administration is most rapid in its re- 

 sults, and the subcutaneous gives the slowest re- 

 sponse, and that the killed sensitized bacteria are 

 most potent in inducing a rapid formation of fer- 

 ment. 



In verification of this latter conclusion, subcu- 

 taneous injections were given, simultaneously, of 

 killed typhoid and killed paratyphoid B, of killed 

 typhoid and killed sensitized paratyphoid B, of 

 sensitized typhoid and killed paratyphoid B, and 

 killed sensitized paratyphoid B. When killed un- 



