OCTOBEE 19, 1900.] 



SCIENCE. 



579 



the last number representing the highest 

 peak. A considerable number of bacteria 

 were obtained in each instance, the highest 

 peak giving 18 per plate for 10 minutes. 

 Quantitative determinations were made of 

 the bacteria in mesa air and that of the 

 residence district of Albuquerque. Five 

 determinations (Nov. -Apr.) on the mesa 

 gave an average of 41.6 bacteria per cubic 

 meter or 1,000 liters. The eleven determi- 

 nations in the city gave 143 bacteria per 

 cubic meter. Both these results are lower 

 than Miquel's figures for Mont-Souris park 

 near Paris in winter, his average for 10 

 years being 170 per cubic meter. It would 

 seem then, that the air of our semi-desert 

 region is freer from bacteria life than other 

 inhabited regions, but not as free as is popu- 

 larly believed. The presence of a consid- 

 erable number of bacteria in the air here, 

 and even on the mountain tops is accounted 

 for mainly by two factors, viz, large quan- 

 tities of dust and relatively high winds. 

 The extreme dryness facilitates dust forma- 

 tion and the high winds distribute what 

 bacteria may be contained in the dust. As 

 to the flora itself, it has already been noted 

 that chromogenic species are prominent. 

 Six out of fourteen species isolated are 

 chromogens. Four of these are micrococci, 

 viz, A^ (salmon-pink), A^ (pink), A^ (sul- 

 phur-yellow) and A^ (orange). Two are 

 bacilli, A^ (yellow) and A^^ (pale-yellow). 

 The remaining colonies are white or gray- 

 white, and with the exception of A^, all are 

 bacilli. Apparently all the species are new. 

 It is worthy of note that this ilora is char- 

 acteristic for a large area of territory as is 

 shown by experiments made at Belen, So- 

 corro, Magdalena, Magdalena Mts. and the 

 Sandia Mts. previously mentioned. This 

 includes territory more than 100 miles dis- 

 tant from Albuquerque. The wide distri- 

 bution of this flora is undoubtedly due to 

 the high winds which have a free sweep 

 over the nearly barren mesas. 



Field Experiments ivith Tomato Rot : By F. 



S. Eaele. 



In a paper read before the Botanical 

 Club at the Columbus meeting* it was 

 pointed out that the ' black rot' or ' blossom 

 end rot' of the tomato was caused by an 

 undetermined species of Bacillus ; and it 

 was suggested that natural infections in 

 the field were probably due to the agency of 

 some small insect. Thrips were suggested 

 as the possible agents of infection since 

 they had frequently been observed in con- 

 nection with the disease. It was also re- 

 marked that there seemed to be more hope 

 in seeking remedies among the insecticides 

 rather than among the fungicides. In or- 

 der to test these views the following field 

 experiments were carried out during the 

 spring of 1900. It was hoped that some 

 of the insecticides used might also be of 

 benefit in controlling the fall worm. Nine 

 plots were set with approximately 100 plants 

 each. All were fertilized and cultivated 

 alike and all were pruned to a single 

 stem and were topped after setting the 

 third fruit cluster. Plots 1, 8 and 9 were 

 checks. The other plots were sprayed 

 eight times each at intervals of three to 

 five days with kerosene, whale oil soap and 

 ' Rose Leaf ' tobacco extract, singly and in 

 combination as is shown by the following 

 table. The kerosene was applied as a 10% 

 mechanical mixture, the soap as a 1^ lb. 

 to 1 gal. of water solution and the ' Rose 

 Leaf as a 1 pt. to 1 gal. solution. The 

 kerosene proved to burn the foliage inju- 

 riously when applied with the other solu- 

 tions and it was dropped from plots 3 and 6 

 after the third spraying. The whale oil soap 

 solution also injured the foliage slightly. 

 The plots were gone over every other day 

 and all wormj^ and rotted fruits were re- 

 moved and counted. The ripening fruits 

 were also counted when picked and the 



* Since published as a part of Ala. Exp. Sta. Bull., 

 No. 109, pp. 20-25. 



