The proper habitat of the lumbricus is the upper and middle part of the small intestine. From this situation it often wanders into the stomach, and frequently gains access to the outer world, not only by the natural passages of the mouth, nostrils, and anus, but also, occasionally, in a more direct way, by perforating the intestinal and abdominal walls. Many cases are on record where lumbrici have passed into the abdominal cavity. In other instances they have lodged themselves within the abdominal viscera and pulmonary organs. When they find their way into the parietes of the abdomen and adjacent parts, they usually give rise to the formation of abscesses requiring surgical interference. As regards the symptoms produced by lumbrici, these vary according to the situation they happen to occupy. The symptoms are also modified by age and temperament. In the stomach and intestines they give rise to colic and shooting pains about the abdomen, followed generally by dyspepsia, nasal itching, nausea, vomiting, and even diarrhœa. Occasionally death supervenes suddenly. A singular case of this kind (the particulars of which I only gathered from a local newspaper) occurred in a boy, thirteen years of age, at the County Gaol at Hertford, in 1873. From Dr Evans’s statement, made at the coroner’s inquest, the sole cause of death appeared to be due to pressure on the windpipe by a worm lodged in the gullet. Sometimes there is cerebral disturbance, attended with general restlessness and convulsive twitchings during sleep. Thus, Dr Woodman has recorded a serious case of convulsions arising from lumbricoid worms, in which, however, a cure was effected by expulsion of the worms. An anonymous writer in the ‘Medical Gazette’ records a case of epilepsy from this cause, whilst another writer in the same journal (1839) mentions an instance where two lumbrici and one tapeworm were associated in the production of similar phenomena. But a much more striking case is also given (anonymously) in the ‘Gazette’ for 1874 (p. 415), where a single lumbricus caused the bearer to be a lunatic for eight years. The victim suffered from cataleptic fits, which lasted for two or three weeks at a time. M. Petrequin, in his ‘Traité Pratique,’ records two cases of amaurosis in young girls produced by lumbrici. A fatal case is recorded by Petrenz, where 200 worms produced enteritis, and another fatal case is given by Roger from perforation (1848). Cases of perforation are also given by Young, by Blair (1861), by Mondière (1839), by Buchner (1851), by Sheppard (1861), and by Luschka (1854), the worms in this last-mentioned case occupying the cavity of the pleura. Cases of severe irritation affecting the genito-urinary organs are given by Dreyfus, Buckingham, and others; and one or two instances are reported where these worms have been discharged from several parts of the body (Neilson, 1833). I may add that the third fasciculus of a work illustrating the collection of