692 



THE MICROSCOPE. 



reparation of the framework, or growth that incessantly 

 goes on in the animal body. 



Classification of the Animal Tissues. — Professor Schwann 

 classifies the fundamental tissues of the human body as 

 follows : — and it will be seen that more than half 

 made up of cellular tissue or simple membrane. 



arc 



1. Simple membrane: employed alone, 

 in the formation of compound 

 membranes 



2. Fibrous tissues. 



3. Cellular tissues. 



Examples : Walls of cells, capsule of 



lens of the eye, sarcolemma of 



muscle, &c. 

 Examples : White and yellow fibrous 



tissue, areola tissue, elastic tissue, 



&c. 

 Examples: Cartilage, fat, pigment, 



grey nervous matter, &c. 

 Examples : Rudimentaiy skeleton of 



invertebrata, bone, teeth, <fee. 



' Examples : Mucous membrane, skin, 

  true or secreting glands, serous and 

 , synovial membranes. 



Examples : Muscle, nerve. 

 Example : Fibro-cartilage. 



4. Sclerous, calcareous, or hard tissues j 



5. Compound membranes: composed-- 



of simple membrane and a layer of i 

 cells of various forms (ephithelium 

 or epidermis), or of areola or con- ' 

 nec.tive tissue and epithelium . .> 



6. Compound tissues; a, those com-i 



posed of tubes of homogenous | 

 membrane, containing a peculiar/ 



substance J 



b, those composed of white fibrous 1 

 tissues and cartilage j 



Cellular or Formative Membrane. — Areolar or connective 

 tissue is generally distributed throughout the body, and 



various forms of this tissue are 

 found ; it is seen uniting to- 

 gether component parts, filling 

 up interstices between them, 

 and affording a support to the 

 blood-vessels and nerves, be- 

 fore they are distributed to the 

 various organs. This tissue is 

 soft, clear, smooth, and ex- 

 tremely minute, being the 

 1-1 2,000th of an inch in dia- 

 /> 7 <1^|3^^^^^^^^t- meter, sometimes less. The 



fibre is usually found United 

 together in bundles : if 

 Fig. 32i.— Fibrovs tissue, Univg the in- these be acted upon by dilute 



Urior of the eggshell, the lime having f - -j f ] „ we ll UD 



heenpreviouslyremovedbyimvierswn aoeilO dOlU, Wiey sucii up, 



. in dilute hydrochloric acid. become transparent, and the 



appearance of fibrous structure is no longer seen, although 



