Contribution to the Flora of Yucatan. 



The peninsula of Yucatan forms the southeastern extremity of 

 Mexico, and constitutes its two Confederate States of Yucatan in the 

 east and Campeche in the west. It projects as a compact rectangular 

 mass between the waters of the Gulf of Mexico on the north and those 

 of the Caribbean Sea on the south, and is separated from the Island 

 of Cuba on the east by the narrow channel of Yucatan, through which 

 pours the current of the Gulf Stream, after being heated in the caul- 

 dron of the southern portion of the Gulf. The coast line of the pen- 

 insula, about 700 miles in extent, presents a uniform, monotonous 

 aspect of an almost continuous line of low sand dunes, which enclose 

 at nearly all points broad lagoons, ranging in depth of water accord- 

 ing to the season. The peninsula has a mean breadth of about 200 

 miles, and a total area of 55,400 square miles, being about the size 

 of the State of Illinois, 



The entire eastern portion of the country is, geologically speak- 

 ing, of recent formation, having been built up in shallow water by 

 polypi, in the form of a low level plateau of porous limestone, having* 

 only sufficient soil caught in its uneven surface to support a dense 

 but dwarfish vegetation. 



From Cape Catoche, its most northeasterly projection, southward 

 along the coast, extend the great Blanquilla reefs, among which are 

 scattered many small islands of coralline rock and clear coral sand. 

 The principal of these are Cankun, Holbox, Cantoy and Mugeres; 

 all lie near the coast, and their formation is apparently too recent to 

 create much soil except the sand of the disintegrated reef rock. 

 About half way down the coast, and ten miles from it in the channel, 

 there is, however, a larger and older island, Cozumel, which is doubt- 

 less a special formation, being considerably higher and older than 

 any of the others. This island has a soil similar to, if not the same 

 as, that of the mainland, and its vegetation is less of the sand-littoral 

 than that of the others. Cozumel is about twenty-five miles long, its 

 highest point being nearly one hundred feet above the sea. In 

 speaking of the flora, Professor Hemsley says in the supplement to 



