306 ON NATURAL HISTORY, 



day does him great injustice, although it might perhaps fairly apply 

 to one of a century and a half ago ; when natural history, which 

 began in the instinctive observation of the habits, and the study of 

 the forms, of living beings, had hardly passed beyond the stage of 

 more or less accurate anecdotes, and larger or smaller collections of 

 curiosities. 



The difference between the ancient naturalist and his modern 

 successor is similar to that between the Chaldjean watcher of the 

 stars and the modern astronomer ; but the scientific progress of the 

 race is epitomized in that of the individual, and may be best exem- 

 plified, perhaps, by tracing out the lines of inquiry into which any 

 person of intelligence, who should faithfully attempt to solve the 

 various problems presented by any living being, however simple and 

 however humble, would necessarily be led. By the investigation of 

 habits, the inquirer is insensibly led into Physiology, Psychology, 

 Geographical and Geological distribution ; by the investigation of 

 the relations of forms, he is no less necessarily impelled into system- 

 atic Zoology and Botany, into Anatomy, Development, and Morpho- 

 logy, or Philosophical Anatomy. Now each of these great sciences 

 is, if followed out into all its details, the sufficient occupation of a 

 lifetime ; but in their aggregate only, are they the equivalent of the 

 science of natural history : and the title of naturalist, in the modern 

 sense, is deserved only by one who has mastered the principles of all. 



So much for the range of natural history. If we consider, not 

 merely the number, but the nature of the problems which it presents, 

 we shall find that they open up fields of thought unsurpassable in 

 interest and grandeur. For instance, morphology demonstrates that 

 the innumerable varieties of the forms of living beings are modelled 

 upon a very small number of common plans or types. (" Haupt- 

 Typen," of Von Bar, whose idea and term are merely paraphrased by 

 " archetype," common plan, &c.) In the animal world we find only 

 five of these common plans, that of the Protozoa, of the Ccxlenterata, 

 of the Molltcsca, of the Anmilosa, and of the Vertebrata. Not only 

 are all animals existing in the present creation organized according to 

 one of these five plans ; but palaeontology tends to show that in the 

 myriads of past ages of which the earth's crust contains the records, 

 no other plan of animal form made its appearance on our planet. A 

 marvellous fact, and one which seems to present no small obstacle in 

 the way of the notion of the possibly fortuitous development of 

 animal life. 



Not merely does the study of morphology lead us into the depths 

 of past time, but it obliges us to gaze into that greater abyss which 



