On Motion in the lumbar division of the spine of birds, by George Oakley Fleming

                                The number of articulations in this part of the spine 
of birds greatly varies; in some, there are many articu-
lations, as in the dorsal and lumbar portions of the 
spine of the sea-gull, (represented in Plate 2, <s>Fig:<\s> letter a) 
whilst in others, there is not more than one moveable 
vertebra, and the remaining dorsal being united to 
each other, and the lumbar vertebrae, with the exception 
of this one, being anchylosed and consolidated with the 
sacrum; thus forming two firm and immoveable 
pieces as in the peacock (v. Plate 3, Fig: 1 & 2), the 
moveable vertebrae being situated between the two; - 
thus two articulations only are formed with the adja-
cent lumbar and dorsal pieces, such as I have just 
described. In the former, the motion of the spine is 
much more divided, and the semilunar articulating 
cavities in the bodies of the vertebrae are not so deep, 
nor are the connecting surfaces of the joints of the 
articulating processes so extensive, though the formation 
of both these articulations, with these exceptions, are 
the same. <s>, and pass obliquely from one vertebra to the 
next, mutually locking them together; and in order to 
most effectually to preclude the possibility of any flection, 
the spinous processes, and sometimes even the bodies of 
the dorsal vertebrae, are immoveably soldered together <\s> 
Although