282 FiKi.i) CoiAMiUAN Museum — Botany, Vol. i. 



line floor being in nearly all parts so great that whatever rain falls 

 quickly filters into cavities, caverns and faults beneath the surface. 

 It is on this account that throughout the region the only residual 

 supply of water available to vegetation is held in the peculiar sar- 

 tenejas, aguadas and cenotes. 



The sartenejas (Maya, Akalchc) are depressions in the floor of 

 the plain, of various sizes, and from a few ounces to several hogs- 

 heads capacity, at the bottom of which sufficient marly soil has been 

 formed to retain such water as falls into them. These soon dry 

 up after the rainy season, and their vegetation lies dormant. The 

 aguadas are simply larger sartenejas, usually of circular outline 

 and from 50 to 100 feet in diameter. These retain stagnant water 

 and maintain a growth of mud plants, such as sedges, fiags and the 

 like, throughout the year. The cenotes (Maya Oonot.*) are deep 

 perpendicular-walled, nearly circular wells, penetrating the floor of the 

 plain and opening into an abundant supply of clear cool water, satu- 

 rated with carbonate of lime. These cenotes are from a few f-eet to a 

 hundred yards or more in diameter, and from 30 to 200 feet deep to 

 the water level, their frequence and extent proving that this great plain 

 is as freely watered far below its surface as most countries are above. 

 The interesting sartenejas are rare, though they are said to be fre- 

 quent in the forests of the south and southwestern regions where the 

 undulation of the plain is more pronounced, they may rightfully be 

 termed the only water supply to the vegetation of the peninsula, 

 though the cenotes assist somewhat in the mists that arise from them 

 during the night, and in the crevices leading to their waters through 

 which creep the roots of the larger trees near by. 



These conditions having been ever present in the geological his- 

 tory of this great plain, it is doubtful if there ever has been more 

 forest or low vegetation than at present. Its plants are not therefore 

 adapting themselves to changed conditions of moisture, but having 

 come into Such existing conditions are attempting to correlate them- 

 selves with their surroundings. 



The year 1H95, in which the principal collections here catalogued 

 were made, was the driest period known on the peninsula for over 

 half a century. During that year the dry season, usually a period of 

 four months, was extended to nine, leaving but three months of par- 

 tial rain. Dr. Gaumer reports that on this account many plants did 



♦The inverted letter O is pronounced in Maya tz. 



