358 Biology in America 



than one way to kill a cat," and, vice versa, to save its life 

 and preserve its kind. 



The depths of the sea are the scene of many a drama. 

 If Science but had the key to Davy Jones' Locker, what a 

 wealth of secrets, tragic as well as comic, she might reveal! 

 There is the fate of the flatfish who fell over on his side 

 before he grew up, and remained lop-sided ever after. And 

 there is the champion cannibal of the animal world, Chias- 

 modus niger, who swallowed his elder brother, acquiring 

 thereby a portly figure of which the most accomplished gour- 

 mand might well be proud. 



Many a terrific battle has been fought upon the sea — 

 titanic struggles of giant squids and mighty whales, battling 

 to the death. Some of these squids have a spread of tentacles 

 of over eighty feet, and the whales, which are probably the 

 invariable victors in these encounters, bear with them well- 



Velella 



Ori^jinal from a specimen in the zoological collection of the Univer- 

 sity of North Dakota. 



earned decorations as evidence of their prowess, in the form 

 of circular scars left upon the skin by the suckers of the 

 squid. 



Floating at the surface of the sea is a host of beings large 

 and small, "creatures of circumstance" driven hither and 

 yon by "every wind that blows." Delicately tinted jelly- 

 fish, Velellas with their tiny sails, the "Portuguese Man of 

 War" with its balloon-like float and its vicious stinging 

 tentacles trailing below, the rotund sunfish, and a legion of 

 crustaceans, molluscs and many others, live at or near the 

 surface. What enables them to float so easily? Some are 

 lighter than the water, as the jellyfish and the sunfish, with 

 its jacket of fat beneath the skin. Still others have floating 

 sacks or bladders containing gas, like the "Portuguese Man 

 of War," while others still, the great majority, have pro- 

 jections of some sort, which increase their "specific surface," 

 i. e., the ratio between surface and weight, and hinder their 

 sinking. A tin plate will sink slower than a leaden bullet 



