INJECTION OF LYMPHATICS. 179 



cure them (Fig. 31). The India-rubber tube con- 

 nected with the canula is closed by the clip g. 



Fig. 31." 



Very fine perforated steel needle for injecting the lymphatics of a part. 



Preparation 7. the mode of injecting the lym- 

 phatics of a tendon may be here described as an 

 example, especially as the subject was omitted when 

 studying the minute structure of tendon. One of the 

 best tendinous structures to choose for the purpose is 

 the fibrous aponeurosis covering the tendon of the 

 triceps extensor femoris of the dog. Two sets of lym- 

 phatics are here met with one in the substance of 

 the tendon, consisting for the most part of vessels ar- 

 ranged conformedly with the direction of the fibres 

 and connected at intervals by transverse branches, 

 so as to form elongated and oblong meshes ; and a 

 superficial one in the areolar sheath which covers 

 the aponeurosis, consisting of vessels forming a close 

 plexus with polygonal rneshes. The latter plexus 

 should first be attempted. Both tube and canula 

 being completely filled with the injecting fluid to 

 the exclusion of air-bubbles, the clip g is closed, and 

 the canula is inserted obliquely for half an inch or 

 more into the areolar sheath, care being taken not 

 to mess the surface of the tissue. This will proba- 

 bly be effected after one or two trials, provided the 

 canula is sufficiently fine and sharp. The clip is 

 then removed, and by turning the handle d, and 

 thus raising the bottle a, the pressure is put on to 

 about an inch of mercury, as indicated by the gauge 

 attached to the injection-bottle. If the insertion of 

 the canula have been fortunate, the blue or red 

 fluid will almost immediately begin to pass into the 

 lymphatic plexus, but should there be no result the 

 pressure may be gradually raised to about two inches ; 

 higher than this it is not as a rule advantageous to 



