CHAPTER III. 



EMBRYONAL AND. MUCOUS TISSUE FAT TISSUE 

 RETICULAR CONNECTIVE TISSUE. 



EMBRYONAL AND MUCOUS TISSUE. 



AT a certain period of embryonic life, those parts 

 of the body which are destined finally to become 

 fibrillar connective tissue consist almost entirely of 

 small spheroidal cells the intercellular substance 

 being absent, or consisting only of a very small 

 quantity of fluid lying between and bathing the 

 cells. As the process of development goes on, some 

 of the cells retain their original spheroidal form, 

 while others change their character, becoming elon- 

 gated and fusiform, often terminating at their ex- 

 tremities in delicate single or branching processes ; 

 others become flattened and assume irregular shapes, 

 sending off branching processes by which they are 

 joined to one another. Hand in hand with this 

 change in the cells there occurs an accumulation 

 of intercellular material, which is at first fluid, and 

 later presents the appearance of a homogeneous 

 gelatinoid substance. Then within the gelatinoid 

 intercellular substance appear fine fibrillae, which 



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