“. 
3 
M. Lamarck, in the beings placed in the lowest or first stage of animal life, 
we are unable to discover organs which demonstrate the existence of sensation, 
a mere irritability of fibre is the whole that is allowed them according to 
this view; it is said that no brain, or nervous system proceeding from 
it can be traced, and the inference that they possess no consciousness or 
volition is hence hastily drawn. Yet if we argue with minds unprejudiced 
by metaphysical systems, from the obvious phcenomena, and guided by the 
first rules of philosophizing, ascribe (in the absence of all direct evidence to 
the contrary) similar effects to similar causes; we cannot, I am persuaded, 
hesitate to ascribe these faculties to the animals in question; whether they 
depend in them on some new and peculiar organization, or whether (which 
considering our imperfect means of observation may well be supposed to be 
the case) they actually possess a nervous system, which, from its minuteness 
and distribution through their frame, has as yet eluded our discovery. The 
vorticella, disturbed by the rays of light or want of food, hurries along till 
it ceases to feel the cause that agitated it. Does this not demonstrate the 
sense of feeling? The irritability of the stomach excited by hunger alone, 
could not spread the numerous tentacula of the Polypi to ensnare its prey, 
and compel these to retain it and guide it to the mouth: no, this demonstrates 
consciousness. 
The arrangement of M, Lamarck commences with the simplest forms of 
animal life; his first class consists of the 1nFusorta, or animals which may be 
discovered in various infusions. ‘The beings it contains are so minute, that 
before the invention of the Microscope, we had no idea of their existence ; 
and even now we know them very imperfectly. They are nevertheless 
highly interesting, and demonstrate conspicuously how very minute an atom 
of matter must be, that is capable of entering into their organic system, and 
being appropriated to their wants. Were it not for the conviction of the im- 
perfect knowledge we possess of these animals, and the insufficiency of our 
means to obtain it, we might be almost led to doubt their continued propa- 
gation, and to have recourse to the supposition of a spontaneous generation ; 
but under these circumstances an hypothesis so contrary to the general ana- 
logies of all animals which we have a full opportunity of observing, cannot 
rashly be admitted. 
The Poxyrr constitute the next class of M. Lamarcx, and form a large 
family of animals, in which we trace a gradual progress to a more compli- 
