386 ENZOOTIC PARAPLEGIA. 



points to disturbance of function, or inability to exercise it in 

 connection with certain parts of the nervous system, probably 

 with the nerve-centre or centres in the cord, or with the nerves 

 themselves. That this disturbance is owing to a diseased con- 

 dition primarily existing in the cord or great nerve ganglia 

 there, does not appear at all probable ; the supposition is nega- 

 tived — 1. By the fact that the condition of paraplegia can be 

 produced at will by the operation of influences acting not 

 directly but indirectly on such centres. 2. By the readiness 

 with which this disordered functional activity disappears under 

 appropriate remedial measures ; disturbance when dependent 

 on primary diseased nerve-centres being not thus readily in- 

 fluenced. The most likely mode of accounting for the con- 

 dition of disturbed innervation is that which regards it as 

 arising from peripheral irritation or influence, this influence 

 being conveyed to and acting upon the nerve-centre which in 

 health ought to originate or determine the controlling force 

 necessarily connected with the performance of certain activities, 

 or by impairing the power of those media by which this force is 

 conveyed. 



The irritation and toxic influence on the nerve-centre and 

 nerve-conducting media can here only be produced apparently 

 in two ways — 1. From the excess in the alimentary canal of 

 ligneous material, which, by its indigestibility and powers of 

 irritation, so influences both nerve-centres and media of nerve- 

 power conduction as to impair or destroy the regulating and 

 conducting influence. 2. From the specific toxic influence 

 exerted by rye-grass when ingested at some particular stage 

 of its growth, and under certain conditions. This latter seems 

 the more probable hypothesis. 



What the particular toxic or paralysis-producing princij)lc 

 contained in the rye-grass at this time is, or how it is pro- 

 duced, if not actually and of itself contained in the grass, 

 and at what stage in the digestive process, it is impossible to 

 say. In some of its features the result bears a certain resem- 

 blance to ergotism. 



Although the evidence, both from clinical and post-mortem 

 examination, is tolerably conclusive that this special form of 

 paraplegia does not owe its origin to mere engorgement of 

 either stomach or intestine Avith food, it is at the same time 



