CHAP. II,] 



THE GAT'S GENERAL FORM. 



17 



flattened in shape, sometimes giving off ramifying processes, which 

 may unite with^ branches from neighbouring connective-tissue cor- 

 puscles. Within the corpuscle is a round or oval nucleus, which 

 contains one or more nuckoli* The structureless substance and 

 fibres form what is called the matrix of the tissue, and the cor- 



Fig. 3. CONNECTIVE, ADIPOSE AND ELASTIC TISSUE. 



A. Loose areolar tissue with fat cells. 



/c. The fat cells. 



13. and C. Magnified view of areolar tissue 

 treated with acetic acid. The white fibres 

 are here no longer seen, and the yellow or 

 elastic fibres with the nuclei come into 

 view. In Fig. B, a series of constrictions 



is produced by the presence of an elastic 

 fibre, which is spirally disposed about the 

 (here swollen and invisible) white fibres. 

 The white fibres may be -^^ of an inch in 

 thickness or even less. 

 D. Fibres of yellow or elastic tissue. 



puscles are cells which are thus more or less plentifully distributed 

 within the matrix. 



Intermixed with the ordinary fibres may be others of a yellower 

 colour (and with a different chemical reaction), known as " elastic 

 fibres," or (< clastic tissue." These fibres may be rendered con- 

 spicuous under the microscope by the addition of acetic acid, which 

 causes the white fibres to swell and become indistinct, thus revealing 

 the existence of the unaffected yellow ones. 



* It may be well to remind the reader 

 that the body of every animal, and there- 

 fore of the cat, consists at first of a single 

 " cell," or minute particle of protoplasm, 

 and afterwards, for a time, of an aggre- 

 gation of such cells whence all the tissues 

 of the body are ultimately derived, and 

 which in different degrees preserve traces 

 of their cellular origin. Cells commonly 



contain a modified internal part or parts 

 called a nucleus or nuclei, when they are 

 said to be "nucleated." It is very 

 common for the nucleus to again con- 

 tain a more minute internal particle, 

 termed a "nucleolus," or it may have 

 several nucleoli. Thus, the connective- 

 tissue corpuscles are " nucleated cells." 



