TISSUES OF THE BODY. 



209 



the connective-tissue under the action of the acetic acid. Whether these 

 finest fibres are all solid or 

 may not be hollow in part, 

 we are not yet able to state. 



By the occurrence of 

 branches on such very fine 

 fibres, and their ever-increas- 

 ing ramification (the diameter 

 of the tubes reaching at times 

 0-0014-0-0022 mm.), an elas- 

 tic network is at length 

 formed (b). This again varies 

 considerably as regards the 

 breadth of its meshes. It 

 usually maintains with its 

 principal fibres the same 

 direction as the bundles of 

 the connective-tissue. 



From these elastic threads 

 we now find transitions to 

 even broader and thicker 

 forms (c), which are decidedly 

 solid, and which, contrasted 

 with the so extensible fibrils 

 of lesser magnitude, display often a considerable degree of brittleness, so 



Fig. 200. Elastic fibres from the human beinpr. . un- 

 branchcd, fine, and finest; 6, a network of tne elastic 

 fibrils; c, a thicker one with branches. 



Fig. 201. From the middle 

 coat of the carotid artery 

 of an ox. a, a mem- 

 brane with a network of 

 the finest elastic fibres; 

 6, a similar membrane 

 feiu-strated at intervals. 



Fig. 202. From the middle and ex- 

 ternal coat of the aorta. 1. An 

 clastic membrane (from the ox) 

 fenestrated to a great extent (a), 

 and with thick bauds between the 

 various holes, 6, c. 2. A network 

 of broad elastic fibres from the 

 whale, which are partly pierced 

 with minute foramina. 



that, in many instances, we can only obtain by dissection short fragments- 

 of the formations in question. 



