Ill ON ANIMAL LIFE IQl 



Whalebone Whale over 70 feet, Sibbald's 

 Whale is said to have reached 80-90, which 

 is perhaps the limit. Captain Scoresby in- 

 deed mentions a Eorqual no less than 120 

 feet in length, but this is probably too great 

 an estimate. 



COMPLEXITY OF ANIMAL STRUCTURE 



The complexity of animal structure is even 

 more marvellous than their mere magnitude. 

 A Caterpillar contains more than 2000 mus- 

 cles. In our own body are some 2,000,000 

 perspiration glands, communicating with the 

 surface by ducts having a total length of some 

 10 miles ; while that of the arteries, veins, 

 and capillaries must be very great ; the blood 

 contains millions of millions of corpuscles, 

 each no doubt a complex structure in itself ; 

 the rods in the retina, which are supposed to 

 be the ultimate recipient of light, are esti- 

 mated at 30,000,000 ; and Meinert has calcu- 

 lated that the gray matter of' the brain is 

 built up of at least 600,000,000 cells. No 



