7 



of the mamilla and not from its pit, the ovary cannot be immersed until it is inmerged in the mamelon; 

 this would be a new finding. 



All this proves that the physiology of the Cacti is still dimmed by obscurities and that the facts that seem 

 incontestable must be taken back. 



All the tubulär Cacti with smooth bark, have an ovary that is very short and becomes considerably 

 elongated, nearly always at maturity. In this way the fruit seems to emerge suddenly from the plant in 

 which it was hidden. This is a phenomenon that without doubt distinguishes the inserted ovary, and is 

 considered to be a precise feature , but it does not apply only to the Mammillaria, the Aulacothele and 

 the Melocactus, but also to the Melanocorpus whose pink wood does not appear uniti its mature.I will 

 even add that some of the Echinocactus with a false cephalium have elongated bark during maturity and 

 because of this have smooth wood in their inferior half. (For example the pink wood of the 

 Echinocactus ingens, etc). In the Anhalonium to the contrary (prismaticum, elongatum, sulcatum, 

 Pelecyphora assiliformis) the bark is only slightly is an exception. Its bark is elongated and remains 

 hidden in the wool of the Vertex and compressed between the tubercles. The Anhalonium Williamsü 

 entirely similar to the Mammillarias. 



Thus I believe we are in complete agreement to reject the characteristic of the possible emergence of the 

 ovary as a mediocre Classification and as a genetic characteristic. I mentioned this to you because in 

 your letters you brought my attention to this subject. I also wanted you to know my ideas as then I could 

 corroborate them with yours. 



A character that seems to me should be considered because it is important, is that there are some species 

 that form a transition. These are derived from the stem which can be smooth or squamous. They are the 

 group where nature itself teils us of the beginning of the series of Cacti: Eumammillaria, Aulacothele, 

 Anhalonium, Melocactus, Discocactus and Malacocarpus. 



I think one could form a first group that could be named Melocactus or Gymnocorpus. The genders of 

 which have among themselves a number of affinities. Each one forms a group that one can observe with 

 certain precision. The Malacocorpus would constitute the transition from the Melocactus to the 

 Echinocactus. The first are recognized by their smooth bark and the second by the mature cephalium. 

 They seem to form a small and quite natural group; they are also distinguished by their color, which in 

 my eyes, constitutes a characteristic that has not been suficiently noticed. 



The Melocactus form a natural group accepted by all botanists, that have singularly multiplied the 

 species. They are also distinguished by their color. They all originate on the shores of the Gulf of 

 Mexico and in the hottest region of the Americas. 



I have nothing to say about the Discocactus, that I do not know. Their tubulär flower is elongated and 

 this seems to be sufficient to distinguish them. 



In regards to the plants that form the 3 groups that you have mentioned with the name of Mammillaria, 

 their characteristics can distinguish them one from another; they merit our highest degree of attention 



