CAUSATION. — GENERAL ANATOMICAL CHARACTERS. 259 



tlieir forms and general improvement in many directions. It 

 is peculiarly a disease of our liner breeds, and is more apt to 

 show itself when those conditions unfavourable to animal 

 life are in operation. So well marked is the influence of ex- 

 ternal agencies in the development of this disease, as of many 

 manifestations of undoubted scrofula, that, like the constitu- 

 tional cachexia, many have come to regard it as capable of 

 propagation apart from an inherited disposition, which is 

 doubtful. 



It is certainly capable of mitigation by attention to the 

 breeding of animals, and to correct hygienic and dietetic con- 

 ditions. Not only is the advent of this tubercular arthritis 

 in the young animal heralded by dyspepsia and disturbed 

 digestion, but a condition of mal-assimilation and perverted 

 formative power in either or both parents seems largely to 

 determine its appearance. 



Although the ordinary form of the appearance of this 

 scrofulous tendency is as specific arthritis with disseminated 

 tubercle or changing products of a specific inflammatory 

 action, it may yet exhibit itself in a fatal form apart from col- 

 lections of the specific adventitious material. 



The production of this constitutional cachexia, which shows 

 itself by the peculiar local tissue-changes, will, when a large 

 and comprehensive view is taken of the subject, appear inti- 

 mately related to disturbed assimilation and perverted tissue- 

 formative power. To the time and manner of performance of 

 the various acts or steps in the complex process of nutrition 

 we must look for the explanation of the production of the 

 unhealthy condition. 



General Anatomical Characters. — Regarded from an ana- 

 tomical point of view, the obvious textural changes here are 

 precisely those of inflammatory action operating under the 

 determining influence of the scrofulous diathesis. These 

 changes are general or local. The former is exhibited — 1. In 

 wide-spread Avant of perfectly developed and carried out 

 formative action, or the begmning of degenerative changes, 

 seen in the unclosed urachus, with its lining membrane 

 studded with a puriform varying-coloured aplastic material, 

 the great blood-conduits and connective-tissue in which all are 

 enclosed being texturally altered, with numerous circumscribed 



17—2 



