302 KAN-ICHIRO MORISHIMA 



rhamnose, raffinose, dulcitol) in broth, in litmus milk, and in 2 per cent 

 glycerol ; or plated on Endo plate ; always, as stated above, with nega- 

 tive results. 



STRAINS MADE INAGGLUTINABLE BY ARTIFICIAL MEANS 



I. Antityphoid rabbit serum (Raw^ling's strain), with a titre 

 of 1 : 10,000 for the homologous and for other laboratory strains, 

 was mixed in proportions of one part of the serum to four parts 

 of the broth in small test tubes. In the course of the experi- 

 ments, this serum being exhausted, another antityphoid serum 

 (made with strain C-51) with a titre of about 1:10,000 was 

 substituted. 



The same lot of broth was used in the controls. 



The stock strains used w^ere "Rawiing's," "C-188," and 

 "Cohen." These were prepared in the manner described above 

 and inoculated into the media. 



1. Rawling's strain. Within thirty-eight days this strain was 

 retransplanted twenty-four times from one tube to another, in 

 two parallel series, one upon antityphoid serum broth, the other 

 on plain broth. During the first ten days, it was transplanted 

 every day and later at intervals of several days. Agglutinability 

 was tested eight times during this period with the same serum. 

 Chart 1 show^s the results. 



As is shown by chart 1, the power of agglutinability in dilution 

 of 1:8000 fell to 1:300 after three days, and twenty-four days 

 later, after fifteen transplants in fresh serum media, the agglu- 

 tinability was recovered. After that there was no remarkable 

 difference between control and serum cultures, although the 

 culture in serum broth was always somew^hat lower in agglutin- 

 ability than the control. The first readings of the serum broth 

 culture after two hours' incubation always showed much lowet 

 agglutinability than the control cultures until the expiration of 

 thirty-five days. The astonishing feature of this experiment was 

 the fact that the serum strain seemed to recover its agglutinability 

 after prolonged cultivation on serum, though at first it had lost 

 it. For this reason, on and after the twenty-third day, ^ve used 



