1124 



TONGUE. 



parts. The superior border presents a double 

 curvature, something like the upper lip of the 

 mouth, i. e. t it curves downwards at its ex- 

 tremities, and has a little dip in the middle. 

 The inferior border, of less extent, is thinner, 

 horizontal, and placed on a plane anterior to 

 the upper. 



The greater cornua are at least half as long 

 again as the body, from the sides of which 

 they project, at first a little outwards and 

 then backwards ; they possess a shaft and two 

 extremities. The anterior extremity is large, 

 club-shaped, tuberculated, and curved in- 

 wards towards the body, for its attachment 

 with which it presents an articular facet ; the 

 shaft tapers gradually posteriorly, and is la- 

 terally flattened, so that it has an outer and 

 inner surface, and an uppei* and lower border. 

 Its outer surface, which is continuous with 

 the anterior surface of the body, looks a little 

 upwards ; its lower border is smooth and 

 rounded; its upper border sharp, and, from 

 the obliquity of the surfaces, of less extent 

 than the lower. The posterior extremity is 

 expanded into a little tubercle, sometimes sur- 

 mounted by an epiphysis. 



The lesser cornua (ossa pisiformia lingualia, 

 of Scemmering) are two little pyramidal or 

 pisiform nodules, projecting upwards, out- 

 wards, and backwards, from the point of 

 union of the greater cornua and body : they 

 are seldom completely ossified. They are 

 the homoloffues in man of a very considerable 

 process (the ceratohyat) in the lower animals, 

 in some of whom the proportion between the 

 lesser and greater cornua is inverted. 



Structure Chiefly compact, but a little 

 cancellous in the body and large extremity of 

 the greater cornua. 



Development. From five points ; one for 

 each element. Vesalius saw a case in which 

 there were six, there being two for the body. 

 The ossification commences in the greater 

 cornua ; it then takes place in the body, 

 where it begins soon after birth ; and, finally, 

 in the lesser cornua, where it does not com- 

 mence till some months after. It proceeds 

 but slowly, and generally leaves a thin lamina 

 of cartilage unossified, so that complete an- 

 chylosis of the different parts into one bone is 

 comparatively rare. 



The morphological value of this bone and 

 its homological relations, will be treated of 

 hereafter. 



b. The hyoglossal membrane or ligament. 

 This is a vertical transverse lamina of very 

 dense areolar tissue, containing a large pro- 

 portion of the yellow element, passing up- 

 wards from the upper border of the body of 

 the os hyoides to the tongue, between which 

 it constitutes a means of union. The mus- 

 cular connection of the tongue with the 

 hyoid bone by means of the hyoglossus is 

 deficient in the central part of the body of 

 that bone, and, consequently, this ligament is, 

 in that situation, the only direct bond of 

 connection. It is dense, yellow, and very 

 elastic, and has a little fat dispersed among it, 

 though this is denied by Bichat. It may be 



traced upwards into the tongue, sometimes as 

 far as an inch. It receives on its anterior 

 face those fibres of the genioglossus that 

 lie immediately above those that are inserted 

 into the hyoid bone, and also some of the 

 intrinsic longitudinal fibres of the tongue that 

 terminate upon it ; posteriorly it is in relation 

 with the upper part of the epiglottis and the 

 mucous membrane reflected upon it from the 

 tongue ; in fact, it immediately underlays the 

 glosso-epiglottid folds. Above, it is gradually 

 lost in the muscles of the tongue ; below, it in 

 part terminates in the upper lip of the body of 

 the os hyoides, and in part is continued on 

 behind this bone, constituting the yellow elas- 

 tic tissue already referred to as being inter- 

 posed between it and the epiglottis. This 

 ligament has been well described by Bichat.* 



c. Median fibrous septum (median carti- 

 laginous lamina, Blandin). Springing from 

 the anterior surface of the last-mentioned 

 structure, interposed between the two ge- 

 nioglossi muscles, passing forwards between 

 these two muscles as far as their genial origin, 

 upwards to the dorsum of the tongue as far 

 forwards as its centre, and thence to the 

 anterior free border of the genioglossi, and 

 a little beyond that border, is a vertical 

 lamina of fibrous tissue. It is thick and dense 

 behind and below, but gradually becomes 

 thinned out as it spreads upwards and for- 

 wards; as it gets thinner it becomes cribriform, 

 like the septum of the corpora cavernosa 

 penis, the areolae giving transmission to the 

 transverse muscles of the tongue, which pass 

 through it from side to side. It varies much 

 in different individuals ; in some it is tolerably 

 dense, in some it is merely a fine areolar web. 

 This structure M. Blandin has dignified with 

 the name of" median cartilaginous lamina," and 

 has described it as consisting of a vertical 

 sheet of that substance of more or less extent. 

 I have, however, looked in vain for any thing 

 like cartilage or fibro-cartilage in any part of 

 it. It appears to me to be nothing more than 

 intermuscular areolar tissue in rather greater 

 amount and density than usual, which hap- 

 pens to be placed in the median plane. It 

 has been supposed by some to be the analogue 

 of the small fusiform slip of cartilage placed 

 beneath the extremity of the tongue in the 

 dog and wolf, with which, however, it has 

 no relation : that structure is essentially dis- 

 tinct. Others have found in it the analogue 

 of the lingual bone, a conception still more 

 far-fetched. It has been supposed to give 

 origin to muscular fibres by its two surfaces. 

 This I have failed in detecting ; certainly it 

 does not give attachment to any of the trans- 

 verse fibres of the tongue, to which it might 

 be supposed it would, if to any; for they 

 may be seen, by transverse sections viewed 

 with the microscope, to pass, without excep- 

 tion, from side to side of the tongue, without 

 any break in their median plane. 



d. Lastly, the investments of the tongue, in- 

 cluding the papillary structures and the true 



* Traite d'Anatomie, t. ii. p. 596. 



