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 are 

 made up of cellular tissue or simple membrane. 



1. Simple membrane: employed alone ' 



in the formation of compound 

 membranes 



2. Fibrous tissues 



3. Cellular tissues 



4. Sclerous, calcareous, or hard tissues 



5. Compound membranes: comj>osed- 



of simple membrane and a layer of 

 cells of various forms (epliithelinm 

 or epidermis), or of areola or con- 

 nective tissue and epithelium . . 



6. Compound tissues ; a, those com- ■ 



posed of tubes of homogenous 

 mend)rane, containing a peculiar 



substance , 



h, those composed of Avhite tibrous ' 

 tissues and cartilage 



Examples : Walls of cells, capsule of 



lens of the eye, sarcolemma of 



muscle, &c. 

 Eixamples : White and yellow fibrous 



tissue, areola tissue, elastic tissue, 



(fee. 

 Examples : Cartilage, fat, pigment, 



grey nervous matter, <fec. 

 Examples : Rudimentai y skeleton of 



invertebrata, bone, teeth, &c. 



Exa)ni)les : Mucous membrane, skin, 

 true or secreting glands, serous and 

 synovial membranes. 



Examples : Muscle, nerve. 



Example : Fibro-cartilage. 



Cellular or Formative Memhrane. — 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, tilling 

 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- 

 meter, sometimes less. The 

 hbre is usually found united 

 together in bundles ; if 

 Fi^.S'ii.—Fihrovs tissue, lining the in- these be acted upon by dilute 



terior of the eggsIu'U. the lime having .. ■ -, ,, ^ ii 



heeitpreviousiyremovedby immersion aCCtlC aClCl, tncy SWCll Up, 



in dilute hydrochloric acid. become transparent, and the 



appearance of fibrous structure is no longer seen, although 



