10 INTRODUCTION. 



Physiology been gradually recognised. We cannot omit mention- 

 ing the names of KRAUSE, VALENTIN, SCHWANN, HENLE in pre- 

 ference to many others whom we could willingly refer to in this 

 field of enquiry 1 . We must limit ourselves to a short survey, 

 and will rather enumerate than describe the different Tissues. A 

 complete description, however compressed, would demand more 

 space than is consistent with the nature of this manual. 



I. Conjunctive Tissue (tela conjunctiva), ordinarily Cellular 

 Membrane or Areolar Tissue, called also by others Formative 

 Tissue, occupies almost everywhere the space between the 

 different parts, and forms, according to Cuvier's well-selected 

 comparison, a kind of sponge, which has the same shape as 

 the whole body which it contributes to form. By long 

 boiling it is dissolved into glue. It consists of bundles of 

 threads, and has no resemblance to the cellular tissue of 

 plants which consists of hexagonal cells. The threads are 

 long, have a somewhat tortuous course and an extreme 

 tenuity (about -^ millim.) 2 . 



II. Adipose Tissue (tela adiposa). Formerly this constituent 

 was not distinguished from the former; it was considered 

 to be cellular tissue containing fat. But it is quite neces- 

 sary to distinguish between them. This tissue consists of 

 vesicles or cells, which, compared with other elementary 

 parts of the animal body, are pretty large (about g . . . ^ mil- 

 lim.). Fat is, with the exception of some constituents of 

 milk in the class mammalia, the only non-azotized substance 

 of the 'animal body and, like most vegetable constituents, 

 rich in Carbon. Fat, except in situations where it occurs 

 as a distinct membrane, forms in the combined state a con- 

 stituent of different tissues and of many animal fluids. 

 III. Vascular Tissue (tela vascularis}. Vessels are hollow cylin- 

 ders, which contain nutrient fluids that circulate through 

 the body. To these belong the Lymphatics as well as the 

 blood-vessels. The larger blood-vessels are composed of 



1 Here too it may suffice to refer to a single work of eminence. J. HENLE, Alge- 

 meine Anatomic, Lehre von der Mischung's-und Formbestandtheilen des menscJdichen 

 Korpers. Leipzig, 1841. 8vo. 



[ 2 A millimeter is about half an English line, or the 24th part of an inch.] 



