THE WESTERN CYCADS ii 



of Spanish occasionally caused some delay, but the 

 Cubans must be credited with an ability to recognize 

 seriously mutilated fragments of their language, if 

 accompanied by appropriate gestures; besides, many 

 of the Cubans speak English, and there are many Ameri- 

 cans in the western part of the island. 



Although the cycads are pecuUarly free from plant 

 diseases and are not likely to carry diseases to other 

 plants, the various quarantine regulations of our Depart- 

 ment of Agriculture cause such delays that it is prac- 

 tically impossible to get living material by mail or express 

 before it has become unfit for microscopic study. Con- 

 sequently I have depended principally upon my own 

 collections, generously supplemented by important 

 stages furnished by my former colleague, Professor 

 Otis W. Caldwell, who gave to the scientific world the 

 first adequate account of the genus and the only account 

 of its life-history. 



DIOON EDULE 



The two genera which may be confined to Mexico 

 (Fig. 4) are Dioon and Ceratozamia; but several species 

 of Zamia also occur there. The general appearance of 

 Dioon edule has already been shown in Fig. i . 



The name Dioon means ''two eggs" and refers to the 

 fact that each scale of the female cone bears two seeds, 

 a feature which is common to all the cycads except one 

 genus. There are three species of Dioon, and some think 

 that there are four or five. 



One of the species, called Dioon edule, because the 

 Mexicans make ''tortillas" from a meal obtained from 

 its seeds, was the object of my first visit to Mexico, 

 undertaken in the spring of 1904. The systematic 



