actual divisiony 1 can only agree and oompletely share, because on- 

 ly after studying the fundamentale thoroughly, should a reforn Job 

 be undertaken. I would only like to Introduce one limitation, that 

 I cannot separate from Cereus neither Phyllocactus ,nor Echinocereus 



Bentham and Hooker 1 s reraarkable genera unf ortunately give proof in 

 the Classification of cacti, of too little study in a difficult ques- 

 tion.- I nust add,that I have returned to to a number of criteria, 

 which I considered very inpo^tant f ormerly ; e . g. the Separation of the 

 stamens of many cerei and Phyllocacti and Eohlnopsls into two group^s, 

 of which the upper and outer ones are separated fron the other, f orming 

 a Corona, as e.g, with Cereus s p e c i o s i s s i nu s , n. y c t i c e 1 1 u, s , E c h i n o p s i s 

 Eyeres a.s.o the case is, is not closely interconneoted' with other 

 growth and fl owering characteri stics as I had believed earlier; it re- 

 nains important enough for a subgroup, but can not be used for a major 

 division of the very large genus Cereus , I nust always c one back , what 

 I have expressed so often, that first an exact study of a large nun- 

 ber of cacti, their flowers and fruit, can help us toward und er Stan- 

 ding this difficult faraily« And I hone, that your efforts in Tie - 

 xico will contribute substantially, to solve many a dif f iculty, and 

 am glad to be able to presnt qu.estions to you in person about various 

 points« 



I occupied myself in. Narles, where I spent 2 nonths, besides the 

 plentifully renresented Conif ers,quite much with Opuntias. Nb. Around 

 New Year ^here flowers magnif icently Taxodium mucroratum , the Cypress 

 of Chapoultepec - You did see this famous tree - Did you. make notes 

 about it ? Collected specinens ? And did you observe other Conifers ? 



As you know, all around the Medi terranian Opuntia f icus indica 

 are grown and has gone wild. In Naples it is common on the market s, 

 mostly an orarge-yellow form with yellow flesh f rarely with light-yel- 

 low-greeuish (apple-like) f'lesh, and most rarely a purple-red one,- 



