ON THE PHYSIOGNOMY OF SEKPENTS. 
the Ophidians, are by far the most complete which have 
ever appeared on this difficult branch of science. I have 
dissected the muscles of serpents of many different genera ; 
but these organs have presented in the different species 
such distinct modifications, that it would require very ex- 
tensive and comparative researches to reduce all these dif- 
ferences to a common type. Such a labour, more interest- 
ing to physiology, would be foreign to the end which I 
proposed to myself in this work. I shall, therefore, con- 
tent myself with presenting a superficial view of the muscles 
of Ophidians in general. 
The muscles, especially those of the trunk, are remark- 
able for the considerable volume observed in some, and the 
extraordinary size of the tendons, which acquire, in some 
species, especially in the true venomous snakes, an uncom- 
mon development. This organization is requisite to give 
that force and activity, with which the undulatory move- 
ments of the body, the principal means of locomotion in 
Ophidians, is executed. The muscles of Ophidians being 
frequently interlaced with each other, it becomes very dif- 
ficult to give an exact description of each individual muscle ; 
and it is not less difficult to compare those organs with 
those of animals of a more elevated scale, and to state the 
modifications they present in departing from their type. 
The upper part of the spine, or, if you will, the posterior 
part, presents a great number of muscles which take their 
origin from the lateral part of the spinous processes, and 
which are united to long tendons inserted into the articu^ 
lar apophyses : they form a compound muscle, which cor- 
responds to the spinalis and semi-spinalis muscles of mam- 
mifera, and which sends, through its whole length, tendons 
to the ends of the spinous apophyses ; it divides on the 
neck in two parts, of which the interior is attached to the 
atlas, while the exterior is prolonged* on the occiput, in 
order to fulfil the functions of levator of the head. The 
muscles which we are describing unite themselves inti- 
mately with the transverse spinous processes which they 
cover ; and this anterior attaches itself to the posterior 
surface of the occiput. The extensor of the spine is 
another very considerable muscle, composed of a great 
