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 phenomena, 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 INFUSORIA, 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 POLYPI constitute the next class of M. LAMARCK, and form a large 

 family of animals, in which we trace a gradual progress to a more compli- 



