VAEIETIES OF COXXECTIVE TISSUE. 



69 



Fig. 41. 



albumin, but not gelatin. In the general course of development 

 of the tissue, fibres, both white and elastic, are formed in the 

 soft matrix, and finally this substance in a great measure disappears. 

 But in certain cases the course is different. The cells may disappear, 

 only the jelly remaining, as in the vitreous humour of the eye; or the 

 corpuscles may branch out and join together in form of a network in 

 the jelly, with the nuclei persisting at the spots whence the threads 

 diverge. The areolar tissue surrounding and imbedding the vessels 

 in the umbilical cord consists of fusiform and ramified corpuscles 

 associated with white fibrillar bundles and elastic fibres, along with 

 much of the soft matrix, which is persistent at the time of birth and 

 is known as the jelly of Wharton. 



2. Ketiform* connective tissue; Reticular tissue, and Cytogenous 

 //ss?^^' (KuUiker) ; Adenoid tissue {Wi&). In this case the matrix dis- 

 appears : neither white nor elastic fibres are developed, but the 

 ramified corpuscles unite 

 together into a reticular 

 or fine trabecular struc- 

 ture (fig. 41) ; either re- 

 taining their nuclei as at 

 a, or losing them and 

 then forming a fine net- 

 work of simple fibres 

 without nuclei as at h. 



That in both forms the 

 tissue is constructed of 

 ramified corpuscles is 

 shown by its withstand- 

 ing boiling in water, 

 whilst it readily dis- 

 solves in hot alkaline 

 solutions. This form of 

 connective tissue enters 

 into the construction of 

 certain organs and tex- 

 tures, where it serves as 

 a supporting fiamework 



to their peculiar elements and their nourishing blood-vessels, and 

 thus becomes a •' sustentacular" tissue {Stiiizgewehe, Germ.). In this 

 way it forms a trabecular network within the lymphatic glands, 

 containing the lymph-corpuscles in its meshes (as at c). So also 

 it is found in the solitary and agminated glands of the intestine, 

 the tongue, and tonsils ; in the thymus gland ; in the spleen ; 

 and in the tissue of the intestinal mucous membrane at certain parts ; 

 in all which situations the meshes contain corpuscles of similar external 

 character with those in the lymphatic glands. But, although thus 

 related to glands and thence named " adenoid " tissue, it exists also as 

 a sustaining structure in the brain and spinal cord, where, with finer 

 branches and closer meshes, it forms an extremely delicate framework 

 supporting the proper nervous substance, and has been called the 

 reticulum (Kolliker). 



* "We use tlie term " retiform," not because it signifies more or less tliau " reticular," 

 liut because tlie latter term is not unfrequently applied to areolar tissue. 



Fig. 41. — Thin Section from the Cortical Part 

 OF A Lymphatic Glaxd, magnified. 



A network of fine trabeculEc formed by retiform or 

 adenoid tissue, from the meshes of which the lymph- 

 corpuscles have been washed out, except at c, where 

 they are left (after His, slightly altered). 



