73 



striking. Tho tiny bactorijil mass referred to contained no chains, no 

 spores, and no involution forms. Tt consisted of slender rods, single 

 or in pairs and very short, as if not now dividing. Exposure of these 

 rods for 10 minutes to a temperature of 74^ C. falling to 60^ C. killed 

 all of them. 



The unexpected feature of this experiment was that after removal 

 to th(^ air growth did not appear in these tubes as soon as it did in the 

 check tubes; in other words, the sojourn in the nitrogen seeiued to have 

 exerted an injurious intiuence. One of the tubes (that inoculated from 

 the solid culture) showed a slight growth at the end of the third day, 

 the other one not until the fifth day. Five days after removal from 

 the nitrogen the bacteria in one tube had made about as much growth 

 as the check tubes made in 48 to GO hours. In the other tube they 

 had made a thin pale yellow growth covering not more than 1 sq. 

 cm. — i. e., not more than one-tenth as much growth as the check tube 

 made in the same time. In the course of another 3 or 4 days the 

 bacteria in both tubes made an abundant bright yellow growth. 



y*v. steioaHi tested at the same time behaved in the same way. At 

 the end of 15 da3^s, when the seal was broken, there was no yellow 

 precipitate or visible slime, colored or colorless, in either tube, The 

 two check tubes showed a distinct growth in 48 hours, and continued 

 to grow in a typical way. On the contrary, there was no visible 

 growth in either tube on the fourth dav after removal from the nitro- 

 gen. On the tifth day in the tube which was inoculated from a solid 

 culture there was a slight yellow growth over a few square millimeters. 

 In the other tube no growth was visible until the eighth day after the 

 removal, and then it was scant}^ This cylinder stood in one-half c.c. 

 water and was still moist. Two da^^s later there Avas a good growth 

 on both cylinders. 



(2) The stock in the second experiment with 1\. hyachithi consisted 

 of 6 tubes of Avhite turnip. Each of 3 was inoculated with one loop 

 of a very cloudy beef -broth culture 6 days old. Each of the other 

 3 was inoculated with one loop of very cloud}' iluid from the bottom 

 of a young bright yellow and very vigorous culcure on coconut 

 after prolonged shaking. Two of the tubes were held as checks. The 

 other 4 were put into 2 U tu])es in the way already described. In 

 each case a test tube (capacit}' 25 c. c.) packed nearl}' full of pyrogallic 

 acid was then tilled with 6i per cent caustic potash water and imme- 

 diately thrust into the other arm of the tube, which was then plunged 

 into the mercuiy. By the end of 24 hours, and probaldy sooner, the 

 absorption of the oxygen was complete — i. e., there was no farther 

 rise of the mercury or chang(» in the color of the pyrogallic acid. 



lic'iulf. — In one of the check tubes growth was plairdy visible on the 

 thii'd day, in the other not. On the sixth day in one check tube there 

 wa» an abundant smooth, wet-shining growth over the whole cvlinder 



