8 BULLETIN 584, U. S. DEPARTMENT OF AGRICULTURE, 
TABLE 1.—Number of infected farms in counties where experimental work was 
carried on, 1913-1916. 
Farms infected. 
State. Cobre 
1913 ! 1914 1915 
Georeial sl eRe SSE oe hs a eed AT ae Deecabuine isa see css \ee ee 764 250 
ICG Hay) ao RS AS RIN SU RSA a UE wim Re Se cepa ee eile Oye Lysates 92 |. 103 
I BGYO RENO Te ays fo aha opie: ape rt) OM pliteees AIM eae Sir A ala ee ys Pa a Hendricks ees a olewe ca ee 446 247 
D Montgomery....-.-.. 376 324 393 
Clay eee can seed. Fete be 130 32 
Dallas eee. 324 302 82 
Marsha to eye 2 arepen |i aya 278 48 
1 ERCES TTC) £95 PO aa A pn Pa pe iendersonbeeeeeesee lee ee eee 157 163 
NUDKG) gULe ee Nar = SM ayes ot ele eae ALR Eee aie aL BTA Che einer ne eae ae 96 19 
Minn CS otal eee eres a-ha eere bela hes emneny 5 0 aut ae eos Renvallea neti eer 8) a ae 616 74 
IMESSO UTR EOE So's) MIRE Se Ae RBM Sr We MLN Ue oe Pettise ee ee 211 324 281 
ENIG DV AS IANS OS is eeeieyae te (acerca A ths ao im ur eae cl Gage and Johnson...|...-..-. 420 86 
PSXOWU HE) at) 1D few eto He Weer st are A a ee ee AL Da VASOTE ae ees ee 2 am 269 116 
FIRCTATICSSO OEY e ah PAB etree SERA mL RR aN Mauryjer icy ee eee es 20 dae 517 462 
1 Only 3 experimental counties in 1913. 
It is unfortunate that the data contained in this table do not cover 
a greater period of time and that similar information can not be fur- 
nished for a number of counties immediately surrounding each ex- 
perimental county. Nevertheless considerable information is afforded 
by the table in its present condition. 
For the purposes of analysis it will be sufficient to consider the 
records of the three original counties. The table shows that with re- 
spect to prevalence of cholera these counties are not in agreement, 
for while the number of outbreaks steadily declined in Dallas County, 
Iowa, they increased slightly in Montgomery County, Ind., in 1915, 
while in Pettis County, Mo., though somewhat reduced in 1915, they 
yet exceeded the record of 1913. What is the explanation of these 
figures and how are these differences to be accounted for? 
A separate consideration of each of these counties is necessary to 
obtain an answer to these questions. As stated above, no figures are 
available on the number of outbreaks in surrounding counties during 
the same period. However, some data relative to total losses from 
cholera in neighboring territory have been obtained, and this informa- 
tion enables us better to understand the records of these three experi- 
mental counties. 
With reference to Dallas County, the table shows that the disease 
was most prevalent in 1913, slightly reduced in 1914, and greatly re- 
duced in 1915. It is a fact that hog cholera in the State of Iowa as 
a whole followed somewhat the same course, being much less in extent 
in 1915 than in either of the two preceding years. Furthermore, a 
carefully prepared estimate, following personal investigations of the 
losses of hogs in 1913, 1914, and 1915 in seven neighboring counties 
where no organized fight against cholera was being carried on, shows 
the same progressive decrease that occurred in Dallas County. The 
