In 1853 Leo had as a tutor a student named Hodounof, a very intelligent young man, who wished not merely to teach him but to impart to him the love of science. Leo was extremely gifted and worked with great facility, but he lacked concentration and was therefore somewhat superficial. This cooled his tutor's enthusiasm, whilst on the other hand he became more and more interested in little Ilia. It was in the course of country walks that they were drawn together. Hodounof used to take Leo for walks in order to study the local flora, and Ilia came out with them, at first for the sake of the exercise. But soon he became interested in the flowers and showed so much taste for botany that he attracted Hodounof's notice; soon the tutor's interest became concentrated on the little boy and he gave him serious attention. It was with a real enthusiasm that Ilia gathered and studied plants; he soon became thoroughly acquainted with the local flora. He thought himself very learned already and wrote memoirs on botany. Passionately fond of teaching, he used to offer all his pocket-money to his brothers and other children to induce them to hear lectures which he gave them. His vocation was fixed from that moment. He was then eight years old. When the family returned to Kharkoff he spent all he had in buying books on natural history, which he read with passionate interest. These contained many things that he could not understand, but his curiosity was all the greater. When he was eleven years old his passion for natural history almost cost him his life. While fishing for hydra in a small pond he was so eager that he fell into the water and was only pulled out with great difficulty. That particular day, his own and his father's name day, was nearly fatal to him, not only through water but through fire. It was a family custom to hold a great gathering of friends and relations at Panassovka on St. Elias's day. Preparations for the feast began days beforehand; the whole household was in a turmoil. On that particular St. Elias's day, so many guests came to Panassovka that there was not enough room in the house to accommodate them all, and the children were transferred to a pavilion outside the house. Whilst in the drawing-room people were talking and playing cards, the servants were holding rejoicings of their own. Towards night-time the majority of the coachmen and footmen brought by the guests were completely drunk; a cigarette imprudently thrown on some hay started a fire. Soon the stables were ablaze and many horses perished in the flames, in spite of every effort to save them. Presently the wind changed in the direction of the pavilion and the thatched roof caught fire. There was a rush to save the children, who were with much difficulty taken out through a window.