Dr. I. Ochoterena,

Casa del Lago,

Chapultepec, Mexico, D.F., Mexico



My dear Doctor Ochoterena:



I avail myself of the first opportunity since my return to write to you acknowledging anew all the manifold kindnesses received from you and from your amiable colleagues of the University and Instituto de Biologia.



On our return north a short distance from Monterrey we met with a slight mishap.  The locomotive of our train was derailed and we were compelled to remain from 9:30 in the evening until half past six in the following morning awaiting the replacement on the track of the huge engine.  Nobody was hurt, as the train had slowed down to take a siding and the only inconvenience which resulted was the fact that I was not able to spend a day in San Antonio, Texas, as I had planned, and a day in New Orleans, but was compelled to go straight through without stopping at both places.  Thanks to the railroad officials at Laredo my reservations eastward were rearranged for me so that I made my connection and traveled in comfort from Mexico City to Pittsburgh, where I arrived on the morning of Friday, May 9th.  Since  my return I have been simply overwhelmed with demands upon my connections and I have been intending constantly to write to you, but this morning find the first favorable  occasion.  My mind is flooded with memories of Mexico and my stay there.  The work of making the plaque, which is to be placed upon the base of the replica of