4 FIELD COLUMBIAN MUSEUM BOTANY, VOL. i. 



Vol. IV, of Godman and Salvin's Biologia Centrali- Americana'. 

 " Taking the present data, the flora of Cozumel is probably more 

 West Indian than continental American in character; for, although 

 the number of species, excluding doubtful ones common to Cozumel 

 and the Continent, but not found in the West Indies, is somewhat 

 larger than the number of West Indian species found in Cozumel, but 

 not on the mainland, those of the latter category are of a more dis- 

 tinct type than those of the former." This may prove true, yet an 

 element enters into the collection upon which Professor Hemsley 

 based his observation of which he had no knowledge; the collector, 

 Dr. Gaumer, a resident of the mainland, collected on Cozumel only 

 such species as he had not observed on the Peninsula. 



This section of Mexico is, in the main, excessively dry, there be- 

 ing no elevations sufficiently high to intercept the moisture-bearing 

 clouds from the Atlantic, while those from the Pacific are shut 

 out by the Sierra Madre range; rainfall is deficient, especially in the 

 northern and southern districts. The heat is also great here, and al- 

 most continuous through the year. A good idea of the climate is 

 given in the following letter recently received from Dr. Gaumer: 

 "March is one of our dryest months, quite hot but very healthy; 

 many of the forest trees are then in bloom, though nearly leafless; 

 for hunting wild animals and birds it is, however, the best month in 

 the year. January and February are not so hot and have more flow- 

 ers, while April and May are much hotter and the flowers are fewer 

 still. In October, November and December, flowers are very abun- 

 dant and the weather cool. June is by far the most delightful month 

 of all the year; Nature, clad in the splendor of iher fresh green attire, 

 is everywhere bedecked with beautiful flowers, among which flit 

 myriads of bright-hued butterflies and brilliant plumaged birds; rains 

 are frequent, however, and form the only drawback to collecting. 

 July, August and September are unsafe months for foreigners to visit 

 this region, although there is no danger if they come in January and 

 remain through this period." 



Although the upper and main portion of Mexico has been for 

 years a favorite collecting ground for botanists, Yucatan has, strangely 

 enough, received but little attention, and so little is known of its flora 

 that Drude in his Handbuch der Pflanzengeographie, says nothing what- 

 ever of the region, though the work was published in 1890. Grisebach, 

 who is best equipped concerning the flora of the neighboring Gulf 

 islands, simply states in his Vegetation der Erde (1884) that the con- 

 ditions of the region prevent luxuriance of vegetable growth, and 

 Hemsley in his report on the botany of Mexico and Central America 

 prepared for the. Biologia quoted above, indicates the paucity of 



