THE HISTORY OF ORGANISMS. 5 



geographical distribution, and the various laws regulating 

 these modifications and adjustments. The paleontologist is ] 

 able actually to see the orderly succession of organisms in the 

 past, and he is constantly called upon to note the relation of 

 the several forms under his view to the environing conditions 

 of their life, and thus to interpret the history of the great races 

 of beings that have peopled the world. 



Botanists and Zoologists observe Individual Characters. The 

 development of the individual organism from the embryo to 

 the mature individual is familiar to us all in its general prin- 

 ciples. We know how the seed or the acorn grows to be- 

 come the flowering plant or the oak tree. We know that the 

 egg, by some mysterious process inside the shell, changes so 

 as to become the chick which cracks its way out, breathes 

 and develops into the crowing cock or the egg-laying hen. 

 In each of these cases the history is the history of an indi- 

 vidual organism. It is the history of a single organism, and 

 the science teaching about these phenomena is the science of 

 Embryology, and is concerned with the laws of individual 

 development. 



Botany and Zoology, too, are mainly concerned with a 

 study of the morphology of the characters of the individual, 

 its form and structure, and particularly the analysis of its 

 organs and their functions, in their morphological relations, 

 the relations of the organs as they are combined for the func- 

 tions of life of the individual. What there is of history is 

 life-history of the individual, and what there is of study of 

 form is of the form of the parts, or of the whole as a complex 

 of such parts, of an individual organism. And what there is 

 of classification is classification to bring out the differences 

 existing between the component parts of separate individuals. 

 In these studies the individual organism is the highest unit, 

 and the investigations are conducted in each case as if there 

 were but one organism : comparisons are between its parts and 

 not with other organisms. 



Paleontologists interested in the History of Species, of Races, and 

 of Groups of Organisms. It is for the paleontologist to speak 

 of the history of races and communities of organisms, that is, 

 to look upon individual organisms as parts of some complex 



