TISSUES OF THE BODY. 



211 



The bundles of connective-tissue which pass from the arachnoid to the 



larger vessels on the base of 



the brain (fig. 204), with other 



isolated fasciculi in the loose 



cellular tissue under the cutis 



and certain serous membranes, 



and that of tendons even, show 



us a very interesting example 



of the artificial production of 



figures extremely like annular 



or spiral elastic fibres, and 



which have even been taken 



for them. To demonstrate 



this, acetic acid is employed 



or prolonged maceration in 



water. 



In the first place we meet 



with fasciculi in which the elas- 

 tic envelope is puffed out and 

 stretched by the action of the 

 reagent, but remains unin- 

 jured, the consequence of 

 which may be twofold as to 

 appearance. Firstly, the gela- 

 tinised substance of the con- 

 nective tissue may be puffed 

 out at intervals into globules, 

 so that annular or at times 

 spiral indentations arise (fig. 

 205, 1, 2, c), or the puffing 

 may be more one-sided, in 

 which case the furrows appear 

 clearer and more distinctly 

 spiral (4). All these furrow- 

 ings are characterised by their 

 delicate outline, which is never 

 double. Further, we may be- 

 sides recognise the presence of 

 the envelope on the cut end of 

 a bundle (2 d), or when it has 

 become separated from the 

 contents, in consequence of the 



penetration of fluid (la) f! & 205. Bundles of connective-tissue from the base of 



r T , f ,, v ' , the human brain, after treatment with acetic acid. 



It trequently OCCUrS, nOW- Some of them have more or less developed elastic 



fibres in their interior. 1. A bundle whose envelope is 

 not torn, but obliquely M-rinkled; a small portion of 

 the latter is separated for a short distance at a. "2. A 

 bundle with annular shrunken porti< ns of the sheath 

 at a, a more strongly pronounced puffing of the sub- 

 stance of the connective-tissue at fc, and a longer por- 



ever, that a number of trans- 

 verse rents are produced in 

 this elastic envelope, in conse- 

 quence of which the substance 

 of the connective-tissue may 

 swell out in globules, while 

 each portion of the envelope be- 

 comes more and more shortened 

 by the pressure, a contraction ensuing, which is rapidly increased by the 



tion of the wrinkled envelope at c, c, from the cut end 

 of which, at d, the contents are protruding. 3. A bundle 

 with annular fragments of the envelope at a, and 

 a larger portion of the latter at 6, more strongly 

 wrinkled. 4. A smaller bundle with uninjured varicose 

 sheath. 



