What is the last name of the person that conducted the December 1900 performance where the man who was called up for military service in 1896 played solo viola?  Answer the above question based on the context below:  Monteux's first high-profile conducting experience came in 1895, when he was barely 20 years old. He was a member of the orchestra engaged for a performance of Saint-Saëns's oratorio La lyre et la harpe, to be conducted by the composer. At the last minute Saint-Saëns judged the player engaged for the important and difficult organ part to be inadequate and, as a celebrated virtuoso organist, decided to play it himself. He asked the orchestra if any of them could take over as conductor; there was a chorus of "Oui – Monteux!". With great trepidation, Monteux conducted the orchestra and soloists including the composer, sight-reading the score, and was judged a success.Monteux's musical career was interrupted in 1896, when he was called up for military service. As a graduate of the Conservatoire, one of France's grandes écoles, he was required to serve only ten months rather than the three years generally required. He later described himself as "the most pitifully inadequate soldier that the 132nd Infantry had ever seen". He had inherited from his mother not only her musical talent but her short and portly build and was physically unsuited to soldiering.Returning to Paris after discharge, Monteux resumed his career as a violist. Hans Richter invited him to lead the violas in the Bayreuth Festival orchestra, but Monteux could not afford to leave his regular work in Paris. In December 1900 Monteux played the solo viola part in Berlioz's Harold in Italy, rarely heard in Paris at the time, with the Colonne Orchestra conducted by Felix Mottl. In 1902 he secured a junior conducting post at the Dieppe casino, a seasonal appointment for the summer months which brought him into contact with leading musicians from the Paris orchestras and well-known soloists on vacation. By 1907 he was the principal conductor at Dieppe, in charge of operas and orchestral concerts. As an orchestral conductor he modelled his technique on that of Arthur Nikisch, under whose baton he had played, and who was his ideal conductor.
A:
Mottl