MICROSCOPIC TEXTURES. 213 



above enumerated are spread throughout nearly the whole 

 frame, while others are confined to certain parts. Thus the 

 blood-vessels and the nerves extend to almost every part of the 

 body, the only certain exceptions being such parts as the 

 cuticle and the enamel of the teeth. Again, what is now 

 called the areolar or connective tissue known, however, in 

 past times by a multitude of names, such as cellular membrane, 

 cellular substance, cellular tissue, reticular tissue spreads 

 throughout every organ and corner of the body, so as to con- 

 nect together the several simpler parts of which each organ is 

 made up. In contrast with these, there are textures proper, 

 named particular textures, confined to one part, such as the 

 osseous tissue and the cartilaginous tissue. 



When the microscope is used for the unravelling of the 

 textures a still greater degree of simplicity is attainable, so 

 that the constructive elements, when regard is had to form 

 only, and not to chemical constitution, may be reduced to the 

 following viz., 1, simple fibre ;' 2, homogeneous membrane, 

 either spread out or forming the walls of tubes or cells ; and, 3, 

 globules or granules, varying in diameter from the 12,000th to 

 the 6000th of an inch. These, with a proportion of amorphous 

 matter, may be regarded as making up the several kinds of 

 structure recognisable in the textures. 



Dr Bennett prefers placing the ultimate microscopic textures 

 under the following four heads viz., 1, molecule-tissues ; 2, 

 cell-tissues ; 3, fibre-tissues ; and, 4, tube-tissues. 



A molecule is a minute body presenting optically the 

 appearance of a point or minute dot. When such a minute 

 dot, by being magnified, presents the appearance of an 

 external ring or margin, which ring or margin is alter- 

 nately dark or light according to the focus under which 

 it is examined, it is termed a granule. Hence molecules 

 and granules are structurally the same. In composition 



