of the muscles of the face and limbs especially, occurring wholly or partly beyond voluntary control, and increasing in violence if predetermined associated movements are attempted. 4. CONVULSIONS-tonic or clonic spasms of the muscles, usually of a reflex character, and therefore considered as centric spinal diseases by Marshall Hall. 5. TETANUS-tonic spasm of the voluntary muscles, and especially of those of respiration. The following terms are applied to the disease according to the part of the body affected: trismus, if the masticatory muscles are engaged; opisthotonos, if the body is drawn backwards by those of the back; emprosthotonos, if drawn forwards by those of the front of the neck and abdomen; and, if bent to one side, pleurosthotonos. 6. HYDROPHOBIA— spasms of the muscles of deglutition and respiration, from increased reflex excitability, and induced by the sight of fluids or efforts to drink them. 7. HEMIPLEGIAloss of motion of one lateral half of the body, dependent on some pathological condition of the intra-cranial prolongation of the cord, or that above the decussation of the fibres of the pyramids. 8. PARAPLEGIA-paralysis of the muscles below a transverse line, dependent on lesions of the cord below the decussation of the fibres of the pyramids. The two latter lesions were sub-divided by Todd according as the muscles were in a rigid or relaxed state. 9. WASTING PALSY, the "paralysie musculaire atrophique" of Cruveilhier, in which organic change in the muscle substance is the primary lesion.

III. Cerebro-spinal diseases, or those affecting both the hemispheres and the cranio-spinal axis. 1. CATALEPSY. Unconsciousness, with a peculiar condition of the muscular system, so that when any part of the body is placed in any position ordinarily fatiguing, it remains rigidly fixed, and even the countenance retains whatever expression it may have had at the time of seizure. 2. EPILEPSY. Loss of consciousness, usually sudden, combined with convulsions-tonic at first, clonic afterwards,

and followed by fatigue and sleep. The symptoms of the affection are, however, most various, and range in all degrees between the "petit mal" and "grand mal" of the French writers. 3. ECLAMPSIA. A form of epilepsy, acute, as it were, and usually due to poisoning, or developed in the parturient female, or in infants.

IV. Neural diseases, engaging the nerves only. 1. NEURALGIA. Pain along the course of a nerve, without any discoverable pathological condition, and usually periodic. 2. SUBJECTIVE SPECIAL SENSATIONSs—as pruritus or formication, affecting those of the skin; perverted tastes, the gustatory nerve; increased or perverted sensitiveness to smells, in the olfactory nerve; tinnitus aurium, affecting the portio mollis; and ocular spectra, or flashes upon the optic nerve. 3. LOCAL SPASMS of special muscles, as cramp; or muscular viscera, as spastic disphagia, due to irritation of their motor filaments. 4. LOCAL PALSY, or loss of function in muscles supplied by some special nerve, as the facial, or in those of common sensation (anæsthesia), taste (ageustia), smell (anosmia), sight (amaurosis), or hearing (cophosis).

The last group of the abnormal conditions of innervation, as arranged by Hughes Bennett, is,

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"V. Neuro-Spinal disorders, in which both the nerves and spinal cord are affected:

"DIASTALTIC OR REFLEX ACTIONS.-To this class belong all those diseases depending on irritation of the extremity of a sensitive nerve, acting, through the cord and motor nerves, on the muscular system, and producing a variety of spasmodic disorders, local or general, far too numerous to mention, which can only be understood by a thorough knowledge of the physiology of the diastaltic or excito-motory system of nerves.'

QUESTIONS FOR EXAMINATION.

JUNIOR.

1. Mention a few purely cerebral diseases.

2. Give the anatomical division of apoplexy, and Abercrombie's.

3. Sketch the pathology of tetanus.

4. How do hemiplegia and paraplegia differ as regards cause? 5. Give some examples of subjective special sensations.

6. What names are applied to the lost senses?

SENIOR.

1. What connexion can you show between abnormal states of nutrition in nervous centres and morbid phenomena, usually considered peculiar to them?

2. What are the principal varieties of insanity?

3. Enumerate all the causes of coma which you remember.

4. What diseases are attended with clonic spasm, and distinguish those which are reflex?

5. Is there any form of palsy inherent to muscles? Who first recognized it?

6. Contrast the phenomena of catalepsy, epilepsy, and eclampsia.

PARASITES,

VEGETAL and animal, infest the human body. Both have been classified according to their position; some plants living on the surface-epiphyta; others dwelling in mucous cavities-entophyta; and animal parasites can be similarly arranged as a epizoa and entozoa.

I. Vegetal. 1. Sarcina ventriculi-an alga discovered by Goodsir in vomited matters which usually are fermenting. Administration of the sulphites which evolve sulphurous acid efficiently checks their production. It has been found in the urine, fæces, fluid of cerebral ventricles, and in a pulmonary abscess. 2. Torula cerevisiae the yeast plant, which frequently forms on saccharine urine, and has been found on various parts of the alimentary passage, probably brought there by beer or other fermenting matters. In cholera patients it has been discovered in the vomit; but it does not seem to have any important connexion with that disease, as once supposed. 8. Leptothrix buccalis-a small yellowish mass which is found on the tongue, mixed with the

3.

fur or epithelium, unless it be morbidly clean. The foregoing are the most accredited algae which have been found in man. Fungi are nearly as frequent. 1. Penicillium glaucum-which occurs in urine, vomited matters, and fæces. 2. Trichophyton tonsurans-which lodges in the hair bulb and shaft. The variety of pityriasis termed versicolor is said to depend on this plant by some; by others upon the microsporon. This disease is contagious, as also are the forms of tinea capitis, which depend upon the same fungus. 3. Achorion Schoenleinii-the plant which constitutes the disease known as porrigo favosa, or "true scald-head." Bennett proved its contagiousness by inoculation. Sycosis menti depends probably on the same parasitic plant. 4. Oidium albicans the fungus found in thrush, aphthæ or muguet, and in diptheria. Other less known vegetal parasites are described in the great monograph of Küchenmeister, translated for the Sydenham Society by Dr. Lankester ; and one plant has been found even infiltrated into the bones of the lower extremity, producing the disease known as "fungus foot," in India.

II. Animal. A. Epizoa. 1. The pediculus, or lousean hemipterous insect inhabiting various parts of the surface of the body, such as scalp and pubis, or burrowing and multiplying enormously in subcutaneous cavities. So is constituted the disease, morbus pediculosus. Pediculi, taken from these different places, have slight zoological peculiarities. 2. Pulex, or flea-a dipterous insect of well-known habits. 3. Pulex penetrans, or chigoe-a troublesome parasite, chiefly found in South America. 4. The acarus scabiei, or itch mite—an animal which was demonstrated to be the cause of scabies by Renucci, a medical student. Latreille named the genus, sarcoptus. 5. Entozoon folliculorum-discovered by Simon in the sebaceous follicles of even healthy indi viduals, but produced in great numbers in persons with coarse greasy skin. It is represented on page 332.

B. Entozoa. Of which the helmintha or intestinal worms are by far the most important for the physician to study. They may be classified in three groups: Nematoidea, Trematoda, and Cestoidea, which include in all 29 species-a number which may be gradually reduced, as some of them are probably but larval forms.

I. Nematoidea. 1. Ascaris lumbricoides, or common round worm, found in the small intestines, especially in children. 2. Ascaris alata, discovered by Dr. Bellingham, and the specimen is preserved in the Pathological Museum of St. Vincent's Hospital. Küchenmeister, without the slightest foundation, doubts that it is " a worm at all." It is so named from two membranous wings on the anterior extremity. It exists in almost every domestic cat. 3. Oxyurus vermicularis, or thread-worm, which lie in clusters in the rectum. 4. Trichocephalus dispar, a worm which was known to Morgagni. It is so common that in 29 persons who died in St. Vincent's Hospital of various diseases, Dr. Bellingham found it in 26, in one of whom 119 existed. Its habitat is the cœcum. 5. Trichina spiralis, an entozoon discovered by Owen in the voluntary muscles. It was believed to be the larva of the preceding species by Küchenmeister; but Virchow, by experiments on rabbits, has proved that it is a distinct animal. Its introduction into the human body in meat has produced death, with symptoms like those of typhus fever. 6. Anclystomum duodenalis, discovered in the gut from which it is named. 7. Strongylus renalis, which has been said to attain six feet in length. 8. Strongylus longevaginatus, distinguished by a sheathed penis, and hence so named, was found in the lung. 9. Spiroptera hominis, which was discharged from the bladder. 10. Filaria medinensis, or Guinea-worm, a formidable parasite which burrows in the subcutaneous and intermuscular areolar tissue. 11. Filaria oculi, found in the globe of the eye and lacrymal passages. 12. Filaria lentis, found by Grafe in a lens he had extracted. 13. Filaria lymphatica was found in the bronchial glands.