242 G. C. SUPPLEE, W. A. Wuitinc, AND P. A. Downs 
In testing the effect of piled plates, the procedure was as follows: Piles 
wide, and containing, in all, 216 plates. The same uniformity of temper- 
_ature at two inches from the top, and the same ventilation, were maintained 
in the incubator as in the first experiment. Likewise, the average of the 
counts of two adjacent plates in each pile was taken as the count for a 
single sample. The two bottom plates in each pile are not included in 
the results, as it was desirable to consider only the counts from the plates 
kept at the same distance from the bottom of the incubator as were those 
in the first experiment; therefore the results are given for only five samples 
to the pile. In table 4, which is constructed to show the relative position 
of each pile in the block, appear the results obtained for each sample, that 
is, the average of each two adjacent plates. 
TABLE 4. Bacrerta Counts OBTAINED FROM SAMPLES OF THE SAME MitK WuHEN PLATES 
Were PILED IN A SouiIpD Biock pDuRING INCUBATION 
Pile 1 Pile 2 Pile 3 Pile 4 Pile5 - Pile 6 
424 ,000 402 , 000 366 , 000 338 ,000 404,000 456 , 000 
419 ,000 346 , 000 336,000 403 ,000 358 , 000 366 , 000 
419 ,000 395 ,000 308 , 000 339 , 000 402 ,000 397 ,000 
368 , 000 367 ,000 272,000 345 , 000 360 , 000 364 ,000 
328 , 000 308 , 000 210,000 191,000 152,000 302 ,000 
Average 392,000 364,000 297 ,000 323 ,000 335 ,000 377 ,000 
Pile 7 Pile 8 Pile 9 Pile 10 Pile 11 Pile 12 
400 , 000 364,000 360,000 319,000 307 ,000 331,000 
369 ,000 316,000 235 , 000 313,000 318 ,000 306 ,000 
393 , 000 373 ,000 79 ,000 245 , 000 290 , 000 348 ,000 
354,000 157 ,000 35,000 126 ,000 33,000 323 ,000 
350 ,000 15,000 7,000 9,060 11,000 309,000 
Average 373 ,000 245 ,000 143 ,000 202 ,000 192 ,000 323,000 
Pile 13 Pile 14 Pile 15 Pile 16 Pile 17 Pile 18 
409 ,000 344,000 403 , 000 361,000 357 ,000 344,000. 
350 , 000 356 ,000 364 , 000 397 ,000 401 , 000 341 ,000 
375 , 000 240 , 000 371,000 342,000 302,000 408 , 000 
380, 000 371,000 295 , 000 283 , 000 201,000 315,000 
306 , 000 386 , 000 237 ,000 211,000 309 , 000 286, 000 
Average 364, 000 339 , 000 334,000 319 ,000 294 , 000 339 , 000 
of 12 plates each were arranged in a solid block, 6 piles long and 3 piles 
