316 



FOETUS. 



upon both sides, the lower jaw ceases to be 

 supported by its muscles, and falls.* 



Influence of disease on the functions of the 

 nerve. The inferences drawn from the anatomy 

 of the nerve and from physiological experiment 

 conjointly have been confirmed in a remarkable 

 manner by the effect of disease of the nerve 

 upon the functions of the parts to which it is 

 distributed: several instances have been pub- 

 lished exemplifying either partially or com- 

 pletely that effect, when, whether from disease 

 of the trunk of the nerve itself or from pressure 

 upon it, its office has been interrupted, all the 

 parts supplied by it are deprived altogether of 

 both their tactile and ordinary sensibility : this 

 loss of sensibility extends to the whole of the 

 corresponding side of the head so far as the 

 distribution of the nerve reaches to the fore- 

 head, temple, ear, surface of the eye and its 

 appendages, cheek, nostril externally and inter- 

 nally, lower part of the face, lips, and mouth, 

 the corresponding half of the tongue, of the 

 palate, and the fauces ; upon all these parts the 

 roughest contact produces no perceptible im- 

 pression ; inflammation is not attended by 

 pain, the most pungent or irritating effluvia do 

 not affect the nostril or the conjunctiva, and 

 the sense of taste is altogether lost in the ante- 

 rior part of the same side of the tongue : at the 

 same time the muscles of mastication the ex- 

 ternal ones at least lose their contractile power, 

 remain inactive during the process and waste, 

 whence are produced a flattening and depres- 

 sion in the site of the temporal and masseter, 

 with prominence of the adjoining points of 

 bone : however the special senses continue un- 

 affected apparently, unless in so far as the sense 

 of contact may be necessary to the perfect or 

 ordinary fulfilment of their function, the olfac- 

 tory function seems much impaired ; the pa- 

 tient is insensible to the impression of ammo- 

 nia, snuff, or other pungent agent, but still ac- 

 knowledges a perception of odour. Vision 

 continues throughout, and appears unaf- 

 fected, unless from the supervention of in- 

 flammation, by which the eye may be spoiled, 

 or from the extension of the disease to the optic 

 nerve or the brain : in the case before alluded 

 to, which the author has witnessed, vision re- 

 mained perfect for a considerable time ; amau- 

 rotic symptoms supervened during the course 

 of the disease ; but even after the occurrence 

 of opacity of the cornea in consequence of in- 

 flammation, the patient could still distinguish 

 light. Hearing appears to have been affected 

 in most, if not all the cases, in which the dis- 

 ease had attained a considerable degree ; it was 

 so in the case seen by the author ; the sense of 

 contact would seem associated with the perfect 

 exercise of the sense. The facial muscles re- 

 tain their contractile power; in the instance 

 alluded to, though the temporal and masseter 

 seemed quite paralyzed, the buccinator acted 

 with energy as ascertained by holding the cheek 

 between the finger and thumb during its con- 

 tractions ; the slight want of adjustment, which 

 may occur about the mouth, seems caused by 



* Magendic, Bell. 



the want of sensation in the lips. Lastly, in 

 all such cases the eye of the affected side is 

 liable to have inflammation excited in it by 

 incidental causes ; for the most part this occurs 

 at an advanced stage of the disease, and can be 

 referred to some exciting cause ; it is attended 

 by but little, if any pain, and opacity of the 

 cornea is an usual result.* 



(For the BIBLIOGRAPHY see NERVE.) 



( B. Alcock.) 



FOETUS, Gr. KV^OC.', Fr. foetus; Germ. 

 die Frucht ; (normal anatomy).' See OVUM. 



FCETUS (abnormal anatomy). Considering 

 the peculiar circumstances of the foetus in utero, 

 we would, at first sight, be inclined to suppose 

 that, although of course exposed to the risk of 

 injury from accidents or diseases occurring to 

 the mother, it would not be liable to many or 

 serious accidents of its own ; nevertheless, ob- 

 servation and experience soon reveal to us a 

 very different state of facts, and force upon us 

 the sad truth that the seeds of life are often 

 sown adulterated with those of infirmity and 

 decay, that disease may mutilate, and death 

 destroy, even before our entrance into life ; for 

 as far as investigation has enabled us to reach, 

 we have reason to believe that the child before 

 birth is not only liable to certain affections 

 which may be considered peculiarly its own, 

 but is also subject to almost all those which 

 affect the adult. 



Of these affections some appear to be, 1. 

 strictly innate in the constitution of the foetus; 

 2. some communicated by infection from the 

 mother's system ; 3. some from the father's sys- 

 tem, or perhaps through that of the mother, 

 she herself not being the subject of the affection 

 entailed, as in certain forms of syphilis, scrofula, 

 and small-pox ; 4. some, from strong mental 

 impressions on the mother; 5. some, arising 

 from morbid alterations in the envelopes of the 

 ovum, the placenta, and cord, or in the uterus 

 itself; 6. some, from the influence of external 

 agents, as falls, blows, pressure, &c. 



The investigation of these abnormal con- 

 ditions is invested with a deep interest, not 

 only as an important pathological inquiry, 

 but as conducive to the adoption of mea- 

 sures calculated to be beneficial to both mo- 

 ther and child; to the child, by suggesting 

 the strong necessity for preventing the exposure 

 of the mother to influences likely to affect the 

 welfare of her unborn offspring, as well as for 

 removing their effects by proper remedial 

 means : and to the mother, by affording us 

 occasionally information of the existence of 

 diseased taints in her system, of which we 

 might otherwise long remain ignorant ; or by 

 guarding her against the ill effects of unhealthy 

 states of the child ; for, although each indivi- 

 dual has a separate existence, there is at the 



* Mayo, Commentaries and Physiology ; Bell, 

 Philosoph. Transactions and on Nerves, 1830 ; 

 Serres, Journal de Physiologic, t. viii ; Noble, 

 Medical Gazette ; Bishop, Medical Gazette, vol. 



