C— GEOLOGY 6 1 



orders of organisms ; the differences that distinguish genera and species 

 are usually trivial and superficial. Hence the restrictions laid on palaeonto- 

 logists, though regrettable, are in no sense crippling. 



Skeletons and shells are particularly informative as to the relation of an 

 organism to its environment, and thus of its habits of life. In this matter 

 a double check is available. Not only can we study the connection between 

 the skeletal and shelly structures of living types and their environment, 

 and so infer the significance of similar characters in extinct forms ; but by 

 a study of the lithology of the sediments in which fossils are found we can 

 deduce the physiographical conditions prevalent at the time of their 

 burial. There is, indeed, little to choose between the opportunities of 

 neontologists and palaeontologists for studying the relation between 

 structure and environment, and, with the shifting scene of geological 

 history, palaeontologists have a unique opportunity to observe the reaction 

 of structures to environmental change. It is here that Palaeontology can 

 make a contribution to biological philosophy no less important than its 

 addition of extinct types to the storehouse of biological facts. 



A short digression into the subject of taxonomy will be useful at this 

 point. In matters of classification Palaeontology has proved a disturbing 

 agent. The so-called ' natural ' classifications of the past, based on 

 conveniently fixed characters, were delightfully simple as well as useful ; 

 but they are out of date and even misleading to-day. Whatever other 

 principles may or may not have been proved by Palaeontology, it has been 

 shown beyond cavil that the characters of organisms do not remain fixed 

 for long. Indeed, it is impossible to hold any longer a belief that they 

 are fixed at all. The new problem thus confronting systematists can be 

 expressed by analogy. The old classification aimed to produce a cata- 

 logue or dictionary in which each item or word was defined as an entity ; 

 the new classification has to devise an etymological concordance, where 

 the history and context of each word is more important than its ephemeral 

 usage. Modern systematists deserve every sympathy as, with scissors 

 and paste, they try to re-edit into a new design the myriad items of their 

 catalogues. 



Considerable confusion has arisen through the unavoidable differences 

 in the bases of classification used in Palaeontology and Neontology. A 

 neontologist can, and should, invoke all the morphological, embryological, 

 ecological, physiological and psychological qualities of an organism as 

 criteria in taxonomy ; a palaeontologist can observe only a fraction of the 

 first three of these qualities. But he can study the chronological order of 

 succession by way of compensation for the rest. There is actually little 

 to choose in the quantity of evidence of taxonomic value available in the 

 two lines of inquiry ; but the emphasis falls differently. In practice a 

 palaeontologist recognises that the chronological factor outweighs all 

 others in significance ; but he envies and borrows from the wide range of 

 information available in Neontology. A neontologist is rarely content 

 to-day to restrict his inquiries to the ephemeral matters that are his 

 rightful scope ; he steals the palaeontological ' thunder ' of succession to 



