6 LETTER OF TEANSMITTAL. 



greatly lessened the prevalence of the disease in the centers where 

 it has longest existed. There is no longer any doubt that, with a 

 continued application of these measures, the disease will soon disap- 

 pear entirely from this country. 



The amount of work necessary to an efficient supervision of the 

 infected districts has been far greater than was anticipated. Thus, 

 for* the eleven months accounted for in the report of 1888, the num- 

 ber of animals inspected reached 305,280, or over 1,000 head per, day. 

 And this inspection includes a careful examination of the lungs of 

 each animal. The number of post-mortem examinations in the same 

 time was 43,176, or 150 per day. The other parts of the work were 

 of course proportionally heavy. The force has been remarkably ef- 

 ficient, and 'although it has often been necessary to adopt arbitrary 

 measures, which have been a hardship to the owners of cattle, there 

 have been few complaints. 



For several years there has been much discussion among well- 

 informed people in regard to the relation between the number of 

 cattle, particularly those maintained for the production of beef, and 

 the population of the country. There has been a great desire on the 

 part of cattle-raisers to know whether the stock of cattle was in- 

 creasing or decreasing as compared with the population. It has also 

 been a question of much interest whether the price of cattle is fixed 

 arbitrarily by the few large firms which control the beef trade, or 

 whether prices here as with other commodities result from the opera- 

 tion of the laws of supply and demand. An earnest attempt has 

 been made to answer these questions so far as possible from the in- 

 formation which could be obtained. Much care was devoted to the 

 collection of the data, and it is believed to be reliable. ( ' 



A section of the report is given to the diagnosis of glanders in 

 horses. There is no more important question for the stock-owners 

 of the United States. Many of our States have laws for the suppres- 

 sion of this disease by the destruction of all affected hors es. ' One of 

 the great obstacles to the enforcement of such laws has been the 

 difficulty of making a reliable diagnosis in the many obscure cases 

 which are encountered. This trouble has been largely overcome by 

 the recent advances made by science in this and other countries. A 

 synopsis of these investigations, together with experiments made by 

 this Bureau in testing the suggested methods of diagnosis, should be 

 of great assistance to all engaged in controlling this dangerous dis- 

 ease. 



The investigations made in regard to the communicable diseases 

 of swine are of very great importance towards clear ing up the nature 

 and cause of such diseases, and indicating the measures which are to 

 be adopted for their prevention. Two diseases have been described, 

 caused by different germs, having quite different characters. These 

 are often complicated with each other, and were first differentiated 



