Besides hibernation Jenner also investigated the habits of the cuckoo, that crux of the biologist which insists on foisting its eggs upon other birds and allowing its orphan young to be brought up in alien nests, while the real young of the deceived foster-parents are often pushed out of their nests by this burly intruder which grows so fast and strong. It is needless to say, this subject interested John Hunter very much and there are a number of letters which passed between them on the subject. It must not be supposed, however, that young Jenner was entirely occupied with his scientific work to the exclusion of social life and recreation. He was one of the best-known men of the county, and was looked upon as a genial companion from whom might be expected on almost any occasion pleasant jests and epigrams, not too biting, with regard to friends and acquaintances. Some of these have been preserved and we quote several of them as indicative of his special vein of humor. ON THE DEATH OF A MISER. "Tom at last has laid by his old niggardly forms, And now gives good dinners; to whom pray?--the worms." ON LORD BERKELEY'S HUNTSMAN, WHO DIED IN THE CHASE. "Determined much higher to hoist up his name, Than Nimrod the hunter, in annals of fame, 'Hark forward!' cried Charles, and gallantly whirled His high-mettled steed o'er the gates of the world." {94} DEATH AND MR. PEACH. A Short Dialogue. N. B.--Mr. P. died in April. "P.--Awhile forbear thy horrid gripe, Do pray, dread Sir! remember Peaches are never fairly ripe 'Till August or September." "D.--To gratify my longing taste, And make thy flavour fine, I had thee in a hot-house placed, And moistened well with wine." "Mr. Peach had shortened his life by the too free use of the bottle." We have said that Dr. Jenner's supreme accomplishment in science was the working out of the vaccination problem to a great humane conclusion. His discovery was no mere accident, nor chance confirmation of a medical tradition. He devoted himself for many years to the study of cowpox, as he had the opportunity to see it, and it is what we know of this investigation, his patience and care in eliminating all the factors of error, that stamped Jenner as a medical scientist worthy of honor. When he began practice in Berkeley, he made many inquiries among his professional brethren, with regard to their opinion of the protecting power of cowpox, but most of them had either paid no attention to such reports, or shook their heads at once, and said they were at most popular traditions, due merely to coincidences and unsupported by any credible evidence. In the face of this, Jenner began to follow John Hunter's advice to investigate. The first careful investigation dates from about 1775, and it took him more than five years to clear away the difficulties surrounding the solution of the question, in which he was interested.