ORGANIZATION. 



39 



ber" of whales), between the muscles (as in "streaky" 

 meat), or in the abdominal cavity, in the omentum, mes- 

 entery, or about the kidneys. The marrow of bones is an 

 example. Globules of fat occur in many Molluscs and 

 Insects ; but true adipose tissue is found only in back- 

 boned animals, particularly the herbivorous. In the aver- 

 age Man, it constitutes about part of his weight, and a 

 single Whale has yielded 120 tons of oil. The fat of 

 animals has the different names of oil, lard, tallow, suet, 

 spermaceti, etc. It is a reserve of nutriment in excess of 

 consumption, serving also as a packing material, and as 

 a protection against cold. 



(7) Muscular Tissue. — If we examine a piece of lean meat, 

 we find it is made up of a number of fasciculi, or bundles 

 of fibres, placed side by 

 side, and bound together 

 by connective tissue. The 

 microscope informs us 

 that each fibre is itself a 

 bundle of smaller fibres ; 

 and when one of these is 

 more closely examined, 

 it is found to be enclosed 

 in a delicate, glossy tube, 

 called the sarcolemma. 

 This tube is filled with 



n , Fig. 11.— Striated Muscular Fibre (of the Pig), 

 very minute, parallel x 200. The coustitueut fibres are seen at a; 



fibrils, averaging TJ ^ jnr cisa fascicu1 ^ « 



of an inch in diameter, and having a striated aspect. 



Tissue of this description constitutes all ordinary muscle, 



or " lean meat," and is marked by regular cross-lines, or 



strice. 



Besides this striated muscular tissue, there exist, in the 

 coats of the stomach, intestines, blood-vessels, and some oth- 

 er parts of Vertebrates, smooth muscular fibres, or mem- 



