PROGRESS OF MICROSCOPICAL SCIENCE. 181 



vided the posterior tibial artery be not wounded. The tendons, after 

 being pinned out on pieces of cork, to prevent shrinking, and having 

 been treated with chloride of gold solution (4 per cent.) and spirit, 

 gave the following results : — Half an hour after the operation blood is 

 seen to be extravasated between the cut surfaces, and for a short dis- 

 tance under the sheath of the tendon. The extravasation does not 

 usually extend deeply into the funnel-shaped wound, but the latter is 

 filled up more or less completely by a process of the sheath, and of 

 the connective tissue outside the sheath. Twenty-four hours after 

 the operation no change is visible in the tendon-cells, particularly 

 none that in any way resembles inflammation. As a rule, the wound is 

 almost entirely filled with the tissue of the sheath, so that any " plastic 

 exudation " that may occur must be very small in quantity. It is only 

 exceptionally that the latter is present in considerable quantity, in 

 which case there is only a small process of the sheath in the wound. 

 In preparations treated with chloride of gold, the exudation appears 

 as a yellow, finely-granular mass, in which a few young cells are 

 scattered. The sheath itself is only slightly inflamed over the place 

 of the incision. If the tendon be examined later on, little change is 

 seen to have occurred in the elementary parts, and none in the tendon- 

 cells. The margins of the wound can always be recognized, and a 

 distinct connection between the contents of the wound and the sheath 

 can be demonstrated. It can also be shown that the tissue occupying 

 the wound is prolonged at the edges of the wound between the separate 

 bundles of fibrillre. By means of this prolongation of the tissue of the 

 wound into the interstices of the tendon-cells, the edges of the wound 

 become, in forty-eight hours, so strong that considerable force is 

 required to make them give way ; and after seventy-two hours or more 

 their separation becomes as difficult as the rupture of the tendon itself. 

 The tissue filling the wound then gradually comes to occupy less room 

 its cells becoming comparatively more approximated ; and in a week 

 from the operation the previously finely granular intercellular sub- 

 stance begins to assume a fibrillated structure. In three or four weeks' 

 time, when the funnel-shaped wound has become linear, nothing definite 

 can be made of the intercellular substance even with high powers. The 

 author cannot ascertain, from direct observation, what becomes of the 

 majority of the elements of the tissue occupying the wound, but is of 

 opinion that, in deciding this point, regard must be had to the amount 

 of original inflammatory swelling of the sheath. In conclusion he 

 says, " whilst on the one hand a true union by the first intention in 

 its histological sense, of tendon does not occur, on the other hand I 

 have found suppuration very rare after incomplete Achillitomy in rats 

 and where it does happen, the tendon-tissue takes scarcely any part 

 in it." 



Insect Muscles : their Structure. — The following are stated to be the 

 conclusions formed by Herr Grunmach : 1. That the structural element 

 of the transversely striated muscular fibre of insects is the " columna 

 muscularis " of Kolliker (muskel-saulchen). 2. That the columna 

 muscularis is composed of a clear lustrous matrix, in which, at definite 

 distances from each other, lie dull prismatic bodies, the so-called 



