TISSUES OF THE BODY. 



235 



139. 



The first indication of the formation of connective-tissue is the 

 appearance at an early foatal period of delicate embryonic cells (fig. 44, 

 p. 66), crowded together, without any membrane, and 

 containing vesicular nuclei. These are held together by 

 a small amount of an albuminous intercellular substance, 

 so that connective-tissue and cartilage commence both of 

 them with extremely similar primary forms. This first con- 

 dition of rudimentary connective-tissue, however, is only 

 very transient. 



The further transformations take place with equal 

 rapidity, and are of different kinds in the various connec- 

 tive-tissue structures. If these remain poor in blood, as, 

 for instance, the tendons, the cells preserve their original crowded position, 

 but become fusiform (fig. 225). If, on the other hand, 

 they become vascular, as is the case with subcutaneous 

 cellular tissue, an outpouring of a plasmatic fluid 

 containing albumen and mucin takes place : the 

 formative cells separate from one another, and assume 

 frequently stellate figures (fig. 226). 



But even already all these cells have undergone 

 metamorphosis. Their processes have broken up into 

 a number of the most delicate fibrillse, which are at first straight, and 

 contain abundant granules of protoplasm between them. Later on the 

 latter withdraw more towards the middle of the cell, and the original cell- 



Pig. 225. Fusi- 

 form cell s from 

 embryonic con- 

 nective-tissue. 



Fig. 226. Stellate cells 

 from the same. 



Fig. 227. Soft connective- 

 trssue from the neigh- 

 bourhood of the tendo 

 Achillis of a human em- 

 bryo of two months old. 



Fig. 228. From the tendo Achillis of a pig 

 embryo 8" long. A, the fusiform cells 

 and their fibrous intermediate matter in 

 profile; B, transverse section (spirit of 

 wine preparation). 



body diminishes to a corresponding degree in volume. The fibrillae 

 then assume gradually a more and more wavy character, and are con- 

 verted into an ordinary bundle of connective-tissue fibrillse (the interstitial 

 molecules disappearing at the same time) (Breslauer and Boll), or into 

 single fibril (Kutznetzoff and Obersteiner). From personal observation we 



