368 



AXILLA. 



brane of the uterus. In the vagina the circular 

 fibres are concentrated at its termination to 

 form the sphincter above mentioned.* 



The clitoris in the Ostrich is continued from 

 the anterior margin of the preputial cavity of 

 the cloaca, and is grooved like the penis of the 

 male; it has also the same muscles inserted 

 in it. A corresponding projection, as before 

 observed, is met with in those birds of which 

 the males have a well developed intromittent 

 organ. 



BIBLIOGRAPHY. Perrault, Description Anato- 

 mique do six oiseaux appelles Demoiselles de 

 Numidie, Mem. de Paris, t. i. .et t. iii. Duverney, 

 Observation Anatomique sur le perroquet arras, 

 sur la cigogne, sur le casuel, Mem. de Paris, t. i. 

 Vicq-d'Azyr, Memoires pour servir a 1'anatomie 

 des oiseaux, Mem. de Paris, A. 1772, 73, 74, 78. 

 Tiedemann, Zoologie, 2ter u. 3tter Bd. Anat. und 

 Naturgeschichte d. Vbgel, 8vo. Landsh. 1808-14. 

 Nitxsch, Aufsatzen, in Meckel's Archiv. B. i. B. ii. 

 and B. iii. * * * * Cotter, Divers, animalium 

 Bceletorum explicationes, fol. Norimb. 1575. Camper, 

 Memoire sur la structure des os dans les oiseaux 

 et de leurs diversites dans les differentes especes, 

 Mem. de Mathem. et Phys. A. 1773. Nitsssch, 

 Osteographische Beitrage zur Naturgeschichte d. 

 Vogel, 8vo. Leipz. 1811. * * * * Herissant, 

 Observations anatomiques sur les mouvemens du 

 bee des oiseaux, Mem. de Paris, A. 1748. Yarrell, 

 on the structure of the beak and its muscles in the 

 Cross-bill, ^Mag. of Nat. Hist. 8vo. Lond. 

 De Reaumur, Sur la digestion des oiseaux, Mem, 

 de I'Ac. des Sc. de Paris, A. 1752. * * * * Bauer, 

 Disquis. circa nonull. Avium systema arteriosum, 

 4to. fieri. 1825. Nitzsch, Obs. de Avium arteria 

 carotide communi, 8vo. Halae, 1829. Barkoio, 

 Untersuchungen liber das Schlagadersystem d.Vbgel, 

 Meckel's Archiv. Jahrg. 1828. Monro, State of 

 facts, &c. and on the lymphatic vessels of oviparous 

 animals, Edin. 1770. Hunter on the absorbents 

 of Birds, in Phil. Trans. 1768. Hewson on the 

 absorbents of Birds, Phil. Trans. 1769. Lauth, 

 Mem. sur les vaissaux lymphatiques des oiseaux, 

 Ann. des Sciences Nat. 1825. * * * * Daubenton, 

 Observations sur la disposition de la trachee- 

 artere de differentes especes d'oiseaux, Mem. de 

 Paris, A. 1781. Latham, Essay on the tracheae, 

 or windpipes, of various kinds of birds, Linn. 

 Trans, v. iv. Fuld, De organisquibus aves spiritus 

 ducunt, 4to. Wirceb. 1816. Yarrell on the trachea 

 of Birds, in Linn. Trans. 1827. Hunter, An 

 account of certain receptacles of air, in birds, which 

 communicate with the lungs, and are lodged both 

 among the fleshy parts and in the hollow bones of 

 these animals, Phil. Trans. Y. 1774. * * * 

 Holier, De cerebro avium et piscium, Verb., van 

 het Maatsch. te Haarlem, Deel 10. Malacarne, 

 Esposizione anatomica delle parti relative all'en- 

 cefalo degli uccelli, Mem. de Verona, t. i. ii. iii. iv. 

 vi. vii. Numan, De medulla spinali avium, &c. 

 8vo. Hallae, 1811. Frank, De avium encephali 

 anatome, 8vo. Berl. 1812, et in Reil's Archiv. 

 B x i. * * # * Vicq-d'Azyr, De la structure de 

 1'organe de 1'ouie des oiseaux, Mem. de Paris, A. 

 1778. * * * * Mery, Observation sur le cercle 

 osseux autour de la cornee de 1'oeil de 1'aigle, du 

 corbeau, et sur la sclerotique de 1'autruche, Mem. 

 de Paris, t. ii. p. 24. Tannenberg, De partibus 

 genitalibus masculis avium, 4to. Getting. 1789 ; 

 Germanice auct. 4to. Getting. 1810. Spangenberg, 

 Disq. circa partes foemineas genitales avium, 4to. 

 Gotting. 1813. Cuvier, Le9ons d'Anat. Comparee, 

 5 vol. 8vo. passim. Rees's Cyclopaedia, art. BIRDS, 

 by Macartney. 



(Richard Owen.) 



- * Purkinje, Symbola; ad Ovi Avium Historiam, 

 4to. 10. fig. 19. 



AXILLA (surgical anatomy) (Fr. Aisselle, 

 Ger. Achselgrube.) Syn. region axillaire y Velp. 

 is the Latin name for the armpit, and is used 

 by anatomists to designate an important region 

 situated between the upper extremity and the 

 thorax. 



The axilla in man is the seat of so many 

 diseases and accidents ; it contains so large a 

 number of nerves, arteries, and lymphatic 

 glands ; and is so frequently interested in sur- 

 gical operations, that a pretty full description 

 of it is allowable on the present occasion. 



When the arm is separated a little from the 

 side, we observe, in the angle between them, a 

 hollow space, which, in the adult, is always 

 covered with hair. This is, in popular lan- 

 guage, the armpit ; but to the anatomist the 

 term axilla conveys a very different notion. 

 By him it is understood to mean a large region, 

 bounded anteriorly by the greater and lesser 

 pectoral muscles, posteriorly by the subsca- 

 pular, the teres major, and a part of the latis- 

 simus dorsi, and internally by the ribs, the 

 intercostal muscles, and the serratus magnus. 

 It presents a basis below, formed of skin and 

 fascia, and an apex above, which opens into the 

 cervical region between the clavicle, scapula, 

 and first rib. Its walls form, therefore, a kind 

 of triangular pyramid, very unequal in their 

 extent, very irregular, and continually under- 

 going alterations in size and shape. Its height 

 is greater in the male than in the female, but 

 its other dimensions are nearly equal. It is 

 to be found in all animals which have an upper 

 extremity, and its uses are subservient to the 

 motions of that limb. 



In the following description the adult male 

 axilla is always supposed to be meant unless 

 otherwise specified. 



When the arm is raised to the horizontal 

 position, we see the floor of this region, the 

 base of our pyramid. This floor is triangular, 

 having its truncated apex at the humerus, its 

 base at the side of the thorax, and its sides 

 formed by the folds of the axilla, that is, the 

 great pectoral in front, the teres major and 

 latissimus behind. It is concave, the concavity 

 looking downwards and outwards. The skin 

 is fine, covered with hair at its upper part from 

 the time of puberty, and secreting, by numerous 

 follicles, a fluid of a peculiar odour. 



By raising the elbow higher than the head we 

 convert the concave into a convex, the folds of 

 the axilla are removed, the skin made tense, 

 and the head of the humerus by descending is 

 made to touch the floor of this region. Press- 

 ing the arm close to the side lowers the 

 floor, shortens the margins, and relaxes all the 

 parts composing the axilla. When the elbow 

 is drawn a few inches from the side, the 

 axillary artery and nerves may be felt along 

 the humerus, and the head of this bone may 

 be distinguished. In searching for disease in 

 the axilla the arm must be placed in all these 

 positions, but we are most likely to detect any 

 abnormal condition of the parts when the elbow 

 is drawn a few inches from the side, and sup- 

 ported without any effort of the patient. 



