Bacterial Flora of the Semi -Desert Region of New Mexico. 227 



If we take Exp. 14, of October 19, 1899, as representative 

 of "mesa" or country air, we have then as compared with the 

 residence district the following ratios: 528:276 and 52.8: 

 394 or approximately 1:6; and for the business district the 

 following: 52.8:1,031 and 52.8:4,320. Assuming the latter 

 to be freer from error, we would have an approximate ratio 

 of 1:80. In other terms, as compared with country air, that 

 of the business district of Albuquerque contains about eighty 

 times as many bacteria. Undoubtedly, at times, the difference 

 is much greater than this even. 



Experiments 22 and 23 are intended to show the difference 

 between the relatively undisturbed air in the morning and 

 the same in the evening after the disturbances due to busi- 

 ness life in the two sections of the town. For this purpose 

 Saturday evening and Sunday morning were selected as 

 showing perhaps the greatest extremes. In the business dis- 

 trict we have the ratio of 685:149 or about 5:1 (see Figs. Ill 

 and IV); and in the residence district 664:167 or about 4:1. 

 This illustrates well the fact that in large part the heavily- 

 laden air of the city is due to the intense activity of business 

 life. 



The flora of the city air in the above was not worked out, 

 as no special interest was involved. It was, as might have 

 been expected, more extensive than that of the country air. 



A few experiments were also made to show for the most 

 part the character of the flora of districts lying at some dis- 

 tance from Albuquerque. They are as follows: 



Exp. 24 — March 19, 1899, p. m. Belen, N. M., 30 miles 

 south of Albuquerque. Three agar plates were exposed in 

 usual way by Rev. T. A. Bendrat, for one hour. No wind. 



March 29: 



PI. 1 — 96 bacteria and 1 mold. 

 PI. 2 — 126 bacteria and 12 molds. 

 PI. 3 — 178 bacteria and 7 molds. 

 Average per 10 min., 22 bacteria. 



The species were as follows: A,, A 3 , A 4 , A 9 , and A n . 

 The yellow colonies predominated, while the red colonies in- 

 variably found at Albuquerque were absent. An is new. 



17 



