Trelease — Botany During the 19th Century. 181 



Century may regard the preparation of a truly natural system 

 even of the higher plants as a part of its legitimate and 

 necessary work, and it may well be that even though this task 

 be accomplished, a like result among the lower cryptogams 

 will be reserved for the next century. At any rate, although 

 DeBary and others have contributed to a rational comparison 

 of the larger groups of thallophytes, a glance at the sytematic 

 memoirs relating to the fungi and algae shows a most obvious 

 if convenient artificialty in their classification. 



MORPHOLOGY AND ANATOMY. 



Some years since, I saw with much interest a palm in the 

 Botanical Garden of Padua on which, toward the end of the 

 Eighteenth Century, the great poet Goethe made some of the 

 observations which led to a formulation of his theory of meta- 

 morphosis in the parts of plants, — a theory which, in the first 

 half of the century just closed, DeCandolle, our own Engel- 

 mann and others put upon a more scientific basis as a funda- 

 mental idea in plant morphology. Toward the middle of the 

 century, the superficial indications afforded by position, grada- 

 tion and malformation of parts were much strengthened by 

 embryological and developmental studies, and it was about this 

 time that the details of cellular structure, grossly known for a 

 couple of centuries, were brought out by Robert Brown and 

 Schleiden, the latter of whom stated in another form for 

 plants the general fact of the origin of every cell from a pre- 

 vious cell, succinctly expressed by the now venerable Virchow, 

 whose eightieth birthday has recently been celebrated in this 

 country as well as in his native land ; for by this time these 

 structures had come to be recognized as the seat of vital 

 manifestations through their protoplasm, which, discovered 

 and named by von Mohl, and the nuclear differentiation of 

 which was observed by Robert Brown in 1835, and which was 

 shown to be similar in animals and plants by Cohn in 1850, 

 Huxley has so happily designated as the physical basis of life. 



Though external morphology and anatomy, the latter even 

 in some of its minuter details, had come down from the past, 

 both may be said to have been made a part of science in the 

 Nineteenth Century, and the fact that homologous members 



