DR. BEALE, ON THE TISSUES. HI 



to its immediate successor, l3ut the processes take place very 

 gradually, and the temporary tissues slowly give place to their 

 more perfect and more permanent successors. When the 

 perfect tj^pe has been attained, new tissue of the same kind is 

 formed, while the old is gradually removed, and in some 

 textures these changes proceed so quickly that elementary parts 

 of every age are to be seen, from the earliest embryonic state 

 to the perfect structure, and from this to the wasted remains, 

 which enable us to complete the history of the changes which 

 occur. 



When an organ which is destined to remain throughout life 

 has been developed, special provision is found to exist whereby 

 the removal of its component elementary organs and the 

 development and growth of new ones is pro\ided for. At every 

 period of life elementary parts and organs are to be met with 

 in every stage of formation, and it sometimes happens that the 

 elementary organs of the kidney, for instance, are impaired, 

 when in an embryonic state. No evidence of any change may 

 appear for a long time, but at length the time arrives when 

 these elementary organs should have attained their perfect 

 state, and should be ready to perform the work of the organ. 

 Their predecessors being worn out, and no new parts developed 

 to take their place, the work cannot be performed, and in the 

 case of an organ like the kidney, liver, or brain, death must 

 result. 



The fibrous capsules of organs are not composed of a form 

 of connective tissue like fascia, merely required for protecting or 

 supporting the structure which it encloses, but veins and lym- 

 phatics are often abundantly distributed in its substance ; and 

 in carefully prepared specimens it is not uncommon to meet 

 with portions of the altered structure of the gland even in the 

 very substance of the capsule. The gland substance not unfre- 

 quently adheres to the capsule so firmly that in tearing it off' 

 portions of the secreting stnicture are torn away with it. In 

 certain morbid changes in the structure this adhesion is much 

 more intimate than in the healthy state. This fact, and many 

 others which might be brought forward are explained upon 

 the view that the oldest portions of the gland structure lie in 

 contact with the capsule, and are absorbed in this situation, 

 certain portions which are incapable of removal in a soluble 

 form remaining, and thus contributing to inci'ease the thick- 

 ness of tlie capsule. 



The arteries, veins, capillaries, and nerves, like other tissues, 

 are perpetually undergoing change, and a certain amount of 

 connective tissue seems to be always associated with these 

 structures. It sometimes exists in such large quantities that 



