00 OF THE CELLULAR SYSTEM. 



Q. What does this intimate union of the serous and 

 fibrous membranes constitute? 



A. They form what are called the sero-fibrous mem- 

 branes. 



Of the Arterial Cellular Texture. 



Q. What are the peculiarities of this texture? 



&. It is remarkably dense; it is never infiltrated with 

 serum; fat does not accumulate in it; it is rarely found in 

 a state of inflammation. 



Q. How is this arterial texture formed? 



#. It is formed by a gradual condensation of the neigh- 

 bouring cellular texture. 



Q. Are the arterial fibres implanted in this dense coat, 

 as the muscular fibres of the stomach, &c. are in the sub- 

 mucous cellular tissue? 



*#. No; the arterial cellular tunic adheres too loosely 

 to the vessels to admit that supposition. 



Of the Venous Cellular Texture. 



Q. What characterizes this texture? 



A. It is not so dense as the arterial, and is more dry. 

 It is not liable to fatty or serous infiltrations. 



Q How is the cellular cylinder of the veins, and arte- 

 ries to be distinguished from the nervous filaments and 

 branches? 



.#. The cellular texture is white ; the nerves are gray ; 

 this is ascertained by deliberate maceration. 



Q. What other canals have a cellular cylinder? 



#. The excretory ducts, those of the pancreas, gall- 



