Near the tropic of Cancer we see several buttes owing to what extent the has here eroded. These still stand of some hundred feet. On all sides one sees the degrading of the butts and the grading of the intermontone plains. The condition here are at hand in the Tropic of Cancer. But unlike them here the grass is greyish white to yellow. There is considerable vegetation and our red soils. In this again we see an active volcano, rising of 2500 feet. They are very recent or they rest in the present tuff layer. Later there are further more remnants of degradation. The floor of the plain at the surface is flues and in other layers beneath is of the nature Creta- cious iron. The mantle is very thin. This is true for the region of Laguna Zera. Just 22 picture around San Luis Potosi in a steep ravine with some cactus. Could see my shadow. One group has Alvarin and Colmenas with Adamon and his family are Prof Ries. South of Potosi the scenery of the north continues. When we get to Obregon there is a very flat valley without plenty more trees...