The Mickoscope. 259 



anastomosis is perfect. The appearance of continuity in the 

 succession of the strife to one another is one of the best means 

 found of determining the fact of anastomosis. This is only 

 imperfectly shown in the figures. 



Anastomoses were found in specimens dissociated either by 

 caustic potash or nitric acid, from the pectoralis, latissimus and 

 biceps femoris, taken from three house mice and a field mouse. 

 The form of the anastomoses is various, the two fibers being 

 sometimes connected by one branch (Fig. 44), sometimes by a 

 number of branches (Fig. 41). The connecting branches are 

 sometimes large (Fig. 40), sometimes small (Fig. 42), and vary in 

 in length from 10-100 /"., and sometimes, when dissociation has 

 not gone too far, they are seen to pass over an intermediate fiber 

 (Fig. 43). 



In some cases the anastomosis is formed by the tip of one of 

 the fibers (Fig. 41) ; in others simply by a connecting branch from 

 a tapering end (Fig. 44). In either case, if the other fiber can be 

 traced, it is found soon to begin to taper and come to an end, 

 generally having branches along the side. The tip of such 

 branches generally has the fringed appearance seen in Fig. 12. 

 Whether this is the result of a rupture or of a simple separation 

 of fibers connected as in Fig. 39, is not known. 



It does not seem unreasonable to suppose that, as branches are 

 given off from all parts of the circumference of a fiber (Fig. 13), 

 there may be a union more or less intimate of one fiber with several 

 of those nearest it. In three cases it was found that one fiber 

 anastomosed with two others (Fig. 45), and in the middle of the 

 biceps femoris of one mouse, where the fibers were in their natural 

 relation, but were particularly transparent, the appearance was of a 

 network of anastomosing fibers. 



These anastomoses were always found in that part of the 

 muscle where tapering ends are in greatest abundance, that is, 

 within the middle third of the muscle. 



Anastomoses of striated muscular fibers have been previously 

 found to occur in the alimentary canal of invertebrates, in the iris 

 of birds, the Ocular muscles of the sheep, and between two branches 

 of the same fiber in a trunk muscle of the horse. 



No special investigation was undertaken to determine the 

 character of the sarcolemma or the striations or the relations of 

 the nuclei, but many of the prepared specimens gave appearances 

 which may be worthy of record. 



