570 THE PRACTICE OF VETERINARY MEDICINE. 



which they -are enabled to migrate and multiply in the 

 various fluids of the animal body, constituting micrococci. 

 It is an indisputable fact that there are local inflammations 

 in every contagious fever ; and in every inflammation there 

 is an abnormal increase of bioplasm, which is accounted 

 for both by the influx of great numbers of wandering cells, 

 and by the retrograde metamorphosis of the tissues of the 

 part. 



Beale speaks of great numbers of microscopic atoms 

 under the name of 'bioplasts.' He tells us, 'the minute 

 contagious bioplast is less than yoo^joo ^^ ^^ ^"^^ i^ 

 diameter, and often so very clear and structureless as to be 

 scarcely distinguishable from the fluid in which it is sus- 

 pended/ 



It has been conclusively shown that acute inflammations 

 produced by chemical or physical means give rise to pro- 

 ducts which are of a contagious nature, and may be 

 successfully inoculated ; and Dr. Burdon Sanderson tells us 

 that he has successfully produced fever by the introduction 

 of minutely small quantities of exudation liquids directly 

 into the blood. 



Most of the above theories have met with many weighty 

 objections, a few of which I would like to notice, but as 

 you are well aware, the various theories and their several 

 objections would make a large volume ; and even though I 

 had the necessary ability to go deeply into the subject, I 

 could not do so in a paper such as mine, which is necessarily 

 restricted as to length. 



The bioplastic theory of Beale, however, seems to me to 

 be the one best worthy of support, and after due considera- 

 tion is the one which, in my humble opinion, is the correct 

 one. It certainly has not met with such strong opposition 

 as the thousand-and-one other theories that have been given 

 to the world. It is founded on actual observation and ex- 



