saying, this species has seeds which are the transition between the seeds of the Coryphanta, just as 

 you described them, that is to say, reticular and smooth, with tuberculated seeds of the Mamilaria 

 conoidea. These seeds are dark brown and have a roughness similar tothe skin of a lime. 



What I have been able to observe until now is that the seeds have clearcut characteristics and truly 

 generic for the Opuntia. For all the other genders, I believe we mustnot try to find seeds that have a 



constant character that may have a generic value. But if they do not provide us with generic 



characteristics, their study is extremely important from the point of view of species character. In 

 relation to the seeds that are typical it will be nearly impossible to confuse seeds from two species 

 that are not very similar. many times I have had the experience while having someone pick the seeds 

 at random from a package where the name was written on the cover, that I was able to identify the 

 seed as written on the label of the package from which the seeds had been taken. 



This year I plan to make a collection of seeds of all the species of Cactus that I have been able to 

 gather. However it is important to note that seeds from the most common species are totally 

 unknown to me. After my collection is slighty more complete I will try to find a good artist capable 

 of making an atlas representing all the series of seeds. I have already asked a horticulturalist in Paris, 

 Mr. Pfersdorf, that specializes in growing cactii, to gather seeds of all species wether new or old, 

 that he is able to. 



It is possible that this study, comparing seeds from diverse species in our collection, will confirm the 

 opinion that I have had for a long time and which I am sure you also have, and that is to 

 considerably reduce the number of species placed in the books or catalogues that deal 

 with Cacti. With this report you certainly will not blame me for not wanting to establish 

 too many new species. I would really like to eliminate many old species and variations 

 from those that I could not be more conclusive.Never the less I tend to destroy a 

 generalized error, that is, that the variations of Cactii in their homeland, tend to 

 hybridization, which is helped by the simultaenous presence of a large number of species 

 that frequently are close to each other, in the same location. This is all an absolute 

 error. This spontaenous hybridization must be extremely rare, if it exists at all. In the first 

 place, in one locality one never fmds but a very few species and the types of each species 

 all look alike without any variations. But going to places further away you will again find 

 the same ones. However in this new location each species will be different of what you 

 saw in the preceding place. Expressing this in other terms, the variations of the species are 

 always determined bv the influence of the locality. they vary from place to place but in the 

 same locality they vary very little. These are species that vary very little in large 

 geographic areas. For example the Echinocactus cormgerus that is found abundandtly 

 near every where in the high plateau (2000 meters). This species shows us the difference 

 in the changes of the different varieties. In reality there are two variations: one with purple 

 thorns and flowers, the other with yellow thorns and flowers, that one fmds specially in 

 the north between San Luis Potosi and Matehuala, from coast to coast. However the two 

 varieties of this species show nearly no variations. One that has many variations is the 

 Echinocactus hexadrophorus that is found in the south and north of Matehuala. Well! 

 from 10 to 10 leagues they nearly completely change. I brought back specimens from 4-5 

 different locations that are quite different among themselves; but in each locations all the 

 specimens are of the same type. 



