14. Mr. W.S. Macteay on the Comparative Anatomy 
to the whole spine, the irregularity of the number of vertebra is 
so great, that even neighbouring species,—such as the dog and 
wolf, the camel and dromedary, the horse and quagga,—differ 
widely in number. Nay more, the same species sometimes 
presents a variety of number in the vertebral joints. The dif- 
ference, moreover, between the maximum numbers of vertebrz 
in Mammalia and birds, as hitherto observed, is 17 in favour of 
Mammalia ; while the difference between their respective mini- 
mum numbers, as hitherto observed, is 9,--Mammalia having 
also the least. Hence, according to what has been said, the 
differences of the number of vertebree in Mammalia is of much 
less consequence, as connected with natural arrangement, than 
those in birds. 
Now let us watch the general variation of the number of 
spinal vertebre in birds; for which purpose I must construct 
my tables upon the data afforded by those which are given by 
M. Cuvier in his Lecons d’ Anatomie Comparée, although I am 
far from conceiving them to be correct. 
Number | Maximum num-| Minimum num-| Extent 
Orders. of species |ber of vertebrz in|ber of yertebrz in of Observations, 
examined. the spine, the spine. variation, 
1. Raprores. . 8 40 36 4 
Pandion. Bullo. 
(The common Sparrow is not 
| here taken into account, be- 
2, INSESSORES . 21 4.2 33 9 4 cause Cuvier does not give 
Pica. Loxia. the number of coccygian 
: vertebra. 
8. RasorEs . . 7 55 37 18 
Struthio. Meleagris, F 
Hemantopus is excluded, 
Z - because Cuvier does not 
4, GRALLATOREs| 13 46 39 ( give the number of yerte- 
Scolopax. Numenius, bre in the coccyx. 
The Petrel is not included, 
ae? by because Cuvier does not 
F te 9 
5. NATATORES . 12 56 39 17 give the number of sacral 
Cygnus, Larus. vertchice 
Hence, 
