324 INTEGUMENTS. 



they are pressed upon by tumours, or irritated from many other 

 causes. This disposition of the cellular substance to assume a 

 ligamentous character, in many of the attachments which are 

 formed between the two tissues, frequently leaves it doubtful 

 with which the membrane under examination should be classed; 

 in some individuals the fibrous substance is predominant, and 

 in others the cellular. This deposite of fibrous matter into cel- 

 lular substance, or rather the change of the latter into it, may 

 be compared to the partial or even perfect conversion of the 

 cartilages of the thorax into bone by an increased deposite of 

 the phosphate of lime. It perhaps will be better understood by 

 repeating that this cellular tissue is an elementary one, where- 

 as the ligamentous is composed of it and ligament. 



In addition to the uses of the cellular substance in forming a 

 nidus for the deposite of all the molecules of the body, and in 

 circumscribing each organ, so as to keep it distinct from the 

 contiguous ones of a different character, its elasticity and yield- 

 ing nature permit it, in the movements of the several parts upon 

 each other, to change its position, and upon the cessation of 

 the active cause, to re-establish itself. Its extreme flexibility is 

 kept up by a continued exhalation of moisture from the arte- 

 ries that ramify through its texture. This cellular serosity, 

 when an animal is recently killed, and its internal parts ex- 

 posed to a cold atmosphere, rises in the form of vapour, and 

 has a particular smell. It is more abundant in certain parts 

 than in others; and, as a general rule, where there is the least 

 adipose matter. Indeed, these two substances seem to exist in 

 an inverse ratio: in a person, for example, who has died very 

 fat, the parts are comparatively dry; whereas, in such as have 

 all the adipose matter wasted by a lingering disease, there is a 

 humidity which quickly disposes to putrefaction; a fact fre- 

 quently exemplified in our dissecting-rooms. The cellular se- 

 rosity is, consequently, more abundant in the scrotum, in the 

 eyelids, and in the penis. Bichat informs us, that he has satis- 

 fied himself by experiments, of its augmentation during diges- 

 tion, during heavy perspirations, and after sleep; which will 

 account for the swelling of the eyelids, so commonly observed 

 in the morning, upon rising. 



This serosity is albuminous, as proved by its being coagu- 



