288 



DESIGN IN NATURE 



Fig. 51. — Posterior view of the superficial and certain of the deep muscles of the back in man. On the left side is exposed the 

 first layer ; on tlie right side, the second layer, and part of the third, a, Occipital bone with superior curved line ; h, ligamentuni 

 nuchse ; c, sterno-mastoid ; d, trapezius ; e, spine of scapula ; /, acromion process of scapula ; g, deltoid muscle ; h, teres major ; i, 

 infra spinatus ; j, latissimus dorsi ; k, crest of the ilium ; I, splenius capitis et colli ; m, levator anguli scapulse ; n, spme of scapula 

 with supra-spinatiis above and iufra-spinatus beneath it; o, rhomboideus minor; p, rhomboideus major; q, vertebral aponeurosis; 

 r, serratus posticus inferior; s, lumliar aponeurosis ; t, spine of ilium ; ninth, tenth, eleventh, and twelfth ribs. The small mimeraLs 

 read from above are : — 7, spine of seventh cervical vertebra ; 1 to 12, spines of the twelve dorsal vertebrae ; 1 to 5, spines of the five 

 lumbar vertebrse. The lowest spines are those of the sacral \'ertebrse and are not numbered. 



d— 



Fi(i. .53. 



Fig. 52. — Lateral view of the muscles of the thorax, abdomen, and hip (human) — the external oblique muscle being removed. 

 a, Lower portion of the great pectoral muscle ; J, lower digitations of the serratus magnus muscle from the fourth to the eighth ribs ; 

 c, lower costal attachments of the latissimus dorsi muscle ; d, trapezius muscle — one of the great fan-shaped muscles of the back ; 

 e, e', divided attachments of the external oblique muscle left in connection with the ribs ; /, /', aponeurosis of the external oblique muscle 

 divided in front of the recti muscles ; g, internal oblique muscle ; h, line where the internal oblique muscle separates to assist in 

 forming the sheath of the recti muscles ; i, gluteus medius muscle ; j,j', gluteus maximus muscle ; /c, anterior superior spinous process 

 of the ilium ; I, tensor vagina; femoris ; m, trochanter major ; n, spine of pubis ; o, rectus femoris. 



The numerals 6 to 12 indicate the ribs counted from above downwards (after Henle). 



Fig. 53. — Superficial muscles of the left chest shoulder, and front of the left arm (human), a, The great fan-shaped muscle known 

 as the pectoralis major ; h, the deltoid muscle engaged in raising the arm. The fibres of these two great muscles (a and h), like those 

 of the diaphragm, practically run in all directions. Such nniscles, for the most part, invest ball and socket or universal joints. 

 Universal joints require a universal arrangement of muscular fil)res to evoke their peculiar powers. Similar arrangements occur at 

 the hip joints, especially in the deeper muscles, c. The biceps muscle which flexes the forearm on the arm; d, the clavicle; 

 e, the sternum. 



Pig. 54. — Transverse section of the human abdomen in the lumbar region, a, a', The two recti abdominis muscles cut across ; 

 h, ditto, the oblique externus ; c, the oblique internus; d, the transversalis abdominis; e, the latissimus dorsi; /, the quadratus 

 lumboruni ; g, the erector spime ; /t, tlie psoas ; i, portion of vertebiul column. All these are seen in transverse section. 



