82 IN LOIVER FLORIDA WILDS 



tropical marine life. For this reason only the 

 hardier West Indian species are found here. 

 Finally, as I shall show in another chapter, the 

 marine life of the Gulf of Mexico was partly 

 derived from the cooler part of the Atlantic, hav- 

 ing migrated around the southern end of the 

 Florida peninsula when it did not extend nearly 

 so far south as it does at present, probably before 

 the keys were formed. 



I have said that this splendid beach is a paradise 

 for the naturalist and collector. He may wander 

 along it in perfect comfort, provided mosquitoes 

 and sand flies are not too troublesome. Some 

 distance back from the beach there is prairie 

 with scattered scrub. As soon as one reaches this 

 his troubles really begin. Over most of it a 

 variety of low thorny bushes and creepers makes 

 any progress most difficult, or even impossible. 

 One is continually forced to turn back and geek 

 another passage. In places the "poor man's 

 plaster" (Mentzilia floridana) completely covers 

 the ground and sprawls over the scrub. It has 

 rather attractive yellow flowers but the stems 

 and under sides of the lobed, deltoid leaves are 

 thickly covered with barbed, glandular hairs. 



