122 BOARD OF AGRICULTURE. 



Concerning the power of ergot to induce abortion, Dun 

 says : " Amongst the lower animals it certainly has no power 

 of producing abortions. It has been given in large and 

 repeated doses to cows, bitches, cats and swine in all stages 

 of pregnancy, but without causing abortion." 



In human medicine its abortive action is by no means gen- 

 eral, and has often been denied, though it is known that it 

 will stimulate uterine contractions in woman, when once 

 begun. That it can cause them is very doubtful, though 

 some vivisectional experiences would seem to indicate that 

 they may occasionally result as deuterotoxic phenomena. 



Having thus endeavored to call all the attention necessary 

 to these collateral etiological momenta, it now becomes our 

 duty to consider, or rather discuss, the evidence still further 

 of what is considered to be tJie cause of enzootic abortion in 

 cows. 



There can scarcely be any doubt that it is an infectious 

 material, but a still more important question is, is it also of 

 a contagious nature? If strictly infectious, but non-conta- 

 ofious, then it becomes domiciled in a localitv — stable — all 

 the cows being exposed to its action. If non-contagious, 

 yet occurring in most of them, then they must have all been 

 in a susceptible, or receptive condition to its action. Again, 

 if not contagious, it would seem that this susceptibility to 

 infection increased with the increasing days of pregnancy 

 from the second or third month to the eighth. 



For a disease to be contagious, it is necessary that the 

 contagious elements multiply, or accumulate in an animal 

 organism, and then cause infection of other animals by 

 means of the excretions, expired air, or other organic deriv- 

 atives from the diseased organism, as in glanders, small-pox. 



We have also a mixed class of infectio-contagious diseases, 

 which are rather uncertain in their infectious outlines. 



I think this trouble belongs to the latter class ; time and 

 experiment only can settle the question. It seems to me 

 that we have to do with infectious elements which develop 

 in special places, from at present unknown causes. If not, 

 how are we to account for the first case in a stable, where no 

 cases have occurred, and no new changes in the cattle made, 



