FIBEOUS TISSUE. 



65 



Fi-. 38. 



from this into the interstice between each two contiguous bundles : 

 this arrangement will be evident on study of the transverse section 

 (fig. 38). On the flat surface of the cells 

 lines are commonly seen running in a 

 longitudinal direction (fig. 37): these are 

 not to be regarded as due either to creases 

 in the cells, or to the presence of an 

 " elastic stripe " as conceived by Boll, but 

 are merely the optical sections of such 

 lamellar extensions as are directed either 

 towards or away from the observer.* At 

 their edges the lamellfB gradually fade off" 

 as they pass between the tendon-bundles : 

 the latter are not completely enclosed 

 by the cells, as was at first supposed by 

 Kanvier, to whom the merit of the dis- 

 covery of these flattened cellular elements 

 belongs, f 



Treatment Avith nitrate of silver solu- 

 tion brings into view corresponding 

 spaces (fig. 39), which commonly appear 

 somewhat larger than the cells them- 

 selves, with which, however, in general 

 form and arrangement they in the main 

 coincide. 



Fi-. 30. 



Fig. 33. — Transverse Skction of 

 Tendon op Mouse's Tail stained 

 WITH Logwood. 175 diameters. 



Tlie flattened processes of tlie 

 tendou-cells (which are stained 

 deeply by logwood) appear in sec- 

 tion as lines, frequently coming 

 off at right angles from the body 

 of the cell. The bundles of fibres 

 are not represented ; they are very 

 irregular, and but incompletely 

 separated by the cell-processes. 



Fig. 39. — Cell Spaces of Tendon of Mouse's Tail, brought into view by treatment 

 WITH Nitrate op Silver. 175 diameters. 



The fibrous and areolar tissues thus agreeing in their ultimate 

 structure, it is not to be wondered at that sometimes the limits between 

 the two should be but ill-defined, and that the one should pass by 

 inconspicuous gradations into the other. Instances of such a transition 

 may be seen in many of the fasciae : these at certain parts consist of 

 dense areolar tissue, but on being traced farther are seen gradually to 

 take on the fibrous character ; and fasciae, which in one body consist of 

 areolar tissue, may be decidedly fibrous in another. 



In chemical constitution also the fibrous tissue is similar to the 

 areolar. It contains about two-thirds of its weight of water; it 

 becomes transparent and hard, when dried, but readily imbibes water 



* From an article received since the above was in type, it would appear that 

 Ranvier has also, from a further study of the subject, arrived at a similar conclusion 

 (Arch, de Phys. No. 2, 1874). 



t Arch, de Physiologic, 1S(J9. 



VOL. II. F 



