It was during this expedition that he discovered a new species of anopheline mosquito, which after identification by Major James, I.M.S., was named after him _Anopheles aitkeni_. During his long service there are to be found in the Annual Reports of the Customs Department frequent mention of Mr. Aitken's good work, but it is doubtful whether the Government ever fully realised what an able literary man they had in their service, wasting his talent in the Salt Department. On two occasions only did congenial work come to him in the course of his public duty--namely, when he was sent to study, from the naturalist's point of view, the malarial conditions prevailing on the frontier of Goa; and when during the last two years of his service he was put in literary charge of _The Sind Gazetteer_. In this book one can see the light and graceful literary touch of Eha frequently cropping up amidst the dry bones of public health and commercial statistics, and the book is enlivened by innumerable witty and philosophic touches appearing in the most unlikely places, such as he alone could enliven a dull subject with. Would that all Government gazetteers were similarly adorned! But there are not many "Ehas" in Government employ in India. On completion of this work he retired to Edinburgh, where most of the sketches contained in this volume were written. He was very happy with his family in his home at Morningside, and was beginning to surround himself with pets and flowers, as was his wont all his life, and to get a good connection with the home newspapers and magazines, when, alas! death stepped in, and he died after a short illness on April 25, 1909. He was interested in the home birds and beasts as he had been with those in India, and the last time the writer met him he was taking home some gold-fish for his aquarium. A few days before his death he had found his way down to the Morningside cemetery, where he had been enjoying the sunshine and flowers of Spring, and he remarked to his wife that he would often go there in future to watch the birds building their nests. Before that time came, he was himself laid to rest in that very spot in sure and certain hope of a blessed resurrection. The above imperfect sketch fails to give the charm and magnetic attraction of the man, and for this one must go to his works, which for those who knew him are very illuminating in this respect. In them one catches a glimpse of his plan for keeping young and cheerful in "the land of regrets," for one of his charms was his youthfulness and interest in life. He refused to be depressed by his lonely life. "I am only an exile," he remarks, "endeavouring to work a successful existence in Dustypore, and not to let my environment shape me as a pudding takes the shape of its mould, but to make it tributary to my own happiness." He therefore urges his readers to cultivate a hobby.