200 ADAPTATION 



for little among fishes. All shapes occur at 

 nearly all times and nearly all places. 



Similarly, blind fishes adapted to caves or 

 other dark places have arisen in many places, but 

 are not necessarily related to each other. The 

 blind fishes of Point Loma are Gobies, and have 

 their nearest relatives in neighboring waters. 

 Those of the Mississippi valley belong to the 

 Amblyopsidas, some of which live in the terranean 

 streams of that valley. The caves of Cuba de- 

 rived their blind fishes from the cracks of the 

 coral reefs in which caves were formed. In 

 South America their nearest relatives are the 

 nocturnal catfishes of Brazil and the blind fishes 

 of Pennsylvania have their nearest relatives in 

 the nocturnal catfishes of Pennsylvania. 



The burrowing lizards of Florida living as 

 earthworms do, look so much like earthworms 

 that the very chickens do not discriminate against 

 them. 



3. Geological convergence or parallelism. Geo- 

 logical records of the simultaneous and similar 

 changes in the form in the mass of species of any 

 area during changing physical conditions are not 

 wanting. For instance, Scott says: — 



" The steps of modernization, which may be observed 

 in following out the history of many different groups 

 of mammals, are seen to keep curiously parallel, as may 

 be noticed, for example, in the series of skulls figured by 

 Kowalevsky, where we find similar changes occurring in 

 such families as the pigs, deer, antelopes, horses, ele- 



