72 



GENERAL ANATOMY OF THE TISSUES. 



Fig. 29. 



Fig. 30. 



iu which this takes 

 place is not vet 

 quite made out, but 

 it is most proba- 

 ble that the cells, 

 as they elongate, 

 change, with their 

 membrane and con- 

 tents, into a ho- 

 mogeneous softish 

 mass, which subse- 

 quently breaks up 

 into a bundle of 

 fine fibrils and some 

 intermediate sub- 

 stance. The de- 

 velopment of the 

 homogeneous connective tissue has as yet been little investi- 

 gated, but it would seem, like the other, to proceed from a 

 fusion of rounded or elongated cells, which are perhaps united 

 by an intermediate substance, in which the metamorphic pro- 

 cess has only gone so far as the development of a homogeneous 

 mass, but has not attained the stage of fibrillation. The bun- 

 dles of the connective tissue, when once formed, grow in length 

 and thickness like the elastic fibres, until they have attained 

 the size which they possess in the adult ; however, there arise 

 subsequently, in many places, additional elements, which are 

 combined with the original ones. The perfect connective 

 tissue, when unmixed, is almost non- vascular, and with regard 

 to nutrition, is certainly very low in the scale, whence it 

 undergoes hardly any morbid changes. The vascular connective 

 tissue is an exception to this rule, but the changes in this 

 case depend not upon any peculiarity in the connective tissue 

 itself, but are determined by the vessels, fat-cells, &c. contained 

 in it. The bundles of fibrils of the connective tissue and the 



Fig. 29. Formative cells of the connective tissue from the skin of the trunk in a 

 sheep's embryo, 7'" long, x 350 : a, cell without any indication of fibrils ; b, with 

 commencing; c, with distinct fibrils. 



Fig. 30. Three formative cells of the areolated connective tissue from the allan- 

 tois of a sheep's embryo, T" long, x 350. 



