9 8 INHERITANCE 



defective or erroneous. But far more than all 

 this, it has opened up to us the science of Embry- 

 ology the most fascinating study a man can 

 pursue which not merely teaches us the several 

 stages through which the complexities of adult 

 structure are reached, but also enables us to 

 reconstruct the pedigrees, the genealogical histories 

 of the various groups of animals, and proves to us 

 that morphological resemblances are no mere 

 accidents, but are indications of true blood relation- 

 ship between one form and another. 



In Botany, results of similar nature have been 

 attained ; and the amount of space accorded in our 

 more recent text-books to the lower orders of plants 

 is cogent evidence of the importance attached to 

 the results of microscopical examination by those 

 best qualified to pass judgment upon them. Nor 

 has the benefit been confined to the student of 

 biological science. To the geologist, the micro- 

 scope is rapidly becoming as important, and in- 

 dispensable as it has long been to the zoologist or 

 botanist. Like his biological brethren, the modern 

 geologist is no longer content with a knowledge, 

 however accurate and minute, of the structure and 

 present condition of the rock he is examining, but 

 recognises that in the microscope he has a means 

 which, used aright, will enable him to unravel the 

 pedigree of the rocks, to reconstruct their past 

 history, and to determine through what series of 

 changes, in what order, and by what agencies, 

 their present condition has been brought about. 



The limits of time and space forbid that I should 



