Zoological Society. 217 



latter origins represent th.e muscidi accessorii ad sacro-lumbulein ; 

 they have not hitherto been described in the class of Birds : to bring 

 them into view, the external margin of the sacro-hnnbaUs must be 

 raised. These accessory tendons run obliquely forward, expanding 

 as they proceed, and are lost in the under surface of the muscle. 



Insertion. By a fleshy fasciculus with very short tendinous fibres 

 into the angle of the sixth rib, and by a series of corresponding fas- 

 ciculi, which become progressively longer and more tendinous, into 

 the angles of the fifth, fourth, third and second ribs, and into the 

 lower transverse processes of the first dorsal and last two cervical 

 vertebrae ; the last insertion is fleshy and strong ; the four anterior 

 of these insertions are concealed by the upper and outer fleshy por- 

 tion of the sacro-lumbalis, which divides into five elongated fleshy 

 bundles, inserted successively into the upper transverse processes of 

 the first three dorsal and last two cervical vertebrae. These last in- 

 sertions seem to represent the continuation of the sacro-luinbaUs in 

 Man, which is termed the cervicalis descendens or ascendens. 



Longissimus dorsi. — This muscle is blended posteriorly both with 

 the sacro-lumbalis and the multifidus spina, and anteriorly with the 

 outer portion of the spinalis dorsi. It extends as far forward as the 

 thirteenth cervical vertebra. Origin. From the inner or mesial half 

 of the anterior margin of the ilium ; from a strong aponeurosis at- 

 tached to the spines of the eighth, seventh and sixth dorsal vertebrae ; 

 and from the transverse processes of the sixth, fifth, fourth and third 

 dorsal vertebrae. Ins. The cameous fibres continued from the second 

 origin, or series of origins, incline slightly outwards as they pass for- 

 ward, and are inserted into the posterior articular processes of the 

 first three dorsal vertebrae, receiving accessor}^ fibres from the spinalis 

 dorsi. The fasciculi from the transverse processes above mentioned 

 incline inwards, and are also inserted into the posterior oblique pro- 

 cesses of the vertebrae anterior to them ; they soon begin to form a 

 series of oblique carneous fasciculi, which become more distinct as 

 they are situated more anteriorly ; they are at first implanted in the 

 vertebra next in front of that from which thej' rise, and then into 

 the vertebra next but one in front ; so that the most anterior of these 

 tendons of insertions, to which can be traced any of the fibres of the 

 main body of the longissimus dorsi, is that which is implanted into 

 the thirteenth cervical vertebra ; it is this fasciculus which is joined 

 by the first or most posterior of the fasciculi of the longus colli 

 posticus. 



A series of oblique carneous fasciculi, evidently a continuation of, 

 or part of the same system with those in which the longissimus dorsi 

 terminates anteriorly, is continued between the upper transverse and 

 the oblique processes of the vertebrae as far forward as the fourth cer- 

 vical vertebra. This series of muscles seems to represent the trans- 

 versalis colli*, which is the anterior continuation of the longissimus 

 dorsi in Mammalia, but it difl^ers in being inserted into the oblique, 

 instead of the transverse processes. In the direction of their fibres 

 * It is the ' grand transversaire ' of Cuvier, loc. cit. p. 282 ; but he describes 

 it as passing from the anterior articular process of one vertebra to the pos- 

 terior articular process of the next in front. 



