32.6 THE HISTORY OF BIOLOGY 



Reform of the animal system 

 Then follows a review of the animal system, which is one of the most 

 brilliant features in the whole of Lamarck's work. Here he draws up the 

 invertebrate system that, except for one or two alterations, has held good 

 ever since. He distinguishes the Infusoria from the Polypi, and the Cirri- 

 pedia from the MoUusca, and thus gets ten invertebrate classes: Infusoria, 

 Polypi, Radiata, Vermes, Insecta, Arachnida, Crustacea, Annelida, Cirri- 

 pedia, Mollusca. Of these classes the Radiata are now divided into two: 

 Ccelenterata and Echinodermata; the Polypi have been grouped with the 

 Coelenterata and the Cirripedia with the crayfish. A number of fresh divisions 

 have certainly been made in modern times, but at any rate Lamarck created 

 a system that, in comparison with Linnasus's invertebrate grouping, repre- 

 sents an extraordinary advance; and it is all the more to Lamarck's honour 

 that he so generously acknowledges his predecessor, whom he calls one of 

 the greatest scientists that have ever existed. But Lamarck was not only a 

 natural philosopher, he was also an expert on form, and as such he was bound 

 to realize the value of the preliminary work carried out by Linnaeus, although 

 he did not accept his hard and fast rules governing species. In this connexion 

 Lamarck describes the difficulties with which the systematist is overwhelmed 

 as a result of the aggravated chaos in scientific nomenclature; to cure this 

 evil he recommends that the nomenclature be fixed by international agree- 

 ment, and this has actually been done, though not until quite recently. 



After reviewing the system of the vertebrate animals, which he has bor- 

 rowed from another zoologist, Dumeril, and is therefore not to be compared 

 in point of interest with the invertebrate system, Lamarck once more takes 

 up the question of the origin of man. He says that the centre of gravity in a 

 man standing erect is situated far in advance of the vertebras, so that muscu- 

 lar effort is required to hold himself upright, which indicates an origin from 

 quadruped animals. He drafts a theory as to man's descent from the anthro- 

 poid apes, but adds that this might have been so if man had not a different 

 origin from the animals. He has evidently not dared to draw the obvious 

 conclusion from his theory, but has taken refuge behind a reservation, simi- 

 lar to that made by Descartes in his hypothetical views on the creation. 

 Lamarck apparently feared that Napoleon would not have felt flattered by a 

 genealogy based on the orang-utan. 



Theoretical speculation on life 

 More than half the Philosophie loologique, however, is taken up with purely 

 theoretical speculations on life and its manifestations, and in this sphere 

 Lamarck again shows his weaker side almost as much as he does in physics 

 and chemistry. Although in the foregoing he constantly makes nature ap- 

 pear as a creative power, he defines it, in his introduction to the speculative 

 section of the work, in the following manner: "Nature — that word that 



