OCR Text |
Show 6 MR. J. H. STEEL ON INDIVIDUAL [Jail. bands beneath the arches of the ribs run from one rib to another, crossing two or three ; these subcostales vary in number, are sometimes continuous posteriorly with the psose, and are covered by the pleuro-costalis, _. Transversalis abdominis varies in the degree of extension ot its tendon towards the internal abdominal ring. The rectus abdominis has a variable number of transverse tendinous markings. LIMBS. Hind.-Sartorius superiorly is attached to the tendon of psoas parvus, to the os innominatum with psoas parvus, or only to the lumbar fascia, sometimes to two or even three of these points. Flexor pedis perforans sometimes presents a distinct muscular belly and tendon, probably a representative of the flexor longus hallucis found in man. Variations of pedal muscles less marked than in fore limb. Fore.-Scapulo humeralis posticus sometimes almost obsolete. Teres externus sometimes divisible into teres proper and acromio-humeralis, as in Ox. Flexor brachii.-Superior tendon has a remarkable piece of red muscular structure on its anterior part, which varies considerably in size. Also the band which runs from this muscle to extensor metacarpi magnus may often be separated nearly to the knee ; careful dissection shows that the inferior extremity of this muscle is somewhat divided into two parts similar to those seen in Dog &c. Pronator teres is of frequent occurrence inside the elbow-joint, arising from the internal inferior prominence of humerus, inserted just below internal lateral ligament, crosses radial artery, vein, and nerve. Generally this muscle is represented only by a small white fibrous band. Extensor pedis.-Thiernesse's and Phillip's muscles sometimes distinct, often imperceptible. Lumbrici vary in number and size. The interossei of the large metacarpal, which in the Equidae form the superior sesamoideal ligament, vary in their amount of muscular structure and in their bulk. NEUROLOGY. Nerves remarkably uniform; sometimes the transverse metacarpal branch is not immediately subcutaneous, but separated from the skin by a longitudinal band of fibrous tissue. SPLANCHNOLOGY. Sometimes a third rudimentary circumvallate papilla a little behind the two usually present. Position of parotid opening varies to a slight degree. Teeth.-Incisors: sometimes only four present in each series, comer permanent incisors having never appeared. Occasionally the upper incisor series has quite become lost-either a result of wear or fracture. The superficial resemblances of this condition to that which occurs in the O x is, of course, of no morphological value. |