230 Philosophy of BoTAirsr. 



infusories, swarm about in the water with rapid motions. 

 Here we find invisible corpuscles, or threads endowed with 

 .distinct sexual properties, and an incredible variety of propa- 

 gation, and such astonishing metamorphoses, as to make the 

 same individual at different periods of his life appear totally- 

 different. 



It is hardly possible for those who are not connected with 

 such investigations to conceive the charm by which an in- 

 conspicuous little plant fastens the observer for hours, days, 

 nay, even weeks, to the microscope, until he succeeds to close 

 up a break in the process of development. No wonder that 

 since half a century nearly all eminent botanists have been en- 

 gaged in the study of the evolution of plants, and that the 

 most important discoveries in plant physiology have been 

 made, especially by German botanists, who conducted the 

 most thoroughgoing microscopical investigations. Not the 

 less in esteem are held abroad contributions from German 

 biological laboratories, and it is very pleasurable to recount 

 the foremost workers whose works are amongst the greatest 

 creations of German science. 



Foremost Schleiden initiated the profounder research by 

 his analysis of the origin of cells in general, and of the germs 

 in particular, in the year 1838. He was followed by Hugo 

 Mohl, of Tubingen ; Alexander Braun, of Berlin ; . Wilhelm 

 Hoffmeister, of Heidelberg; Hanstein, of Bonn; De Bary in 

 Strassburg, and Sachs in Wiirzburg, all of them now defunct. 

 Among the living are Naegeli in Munich, and Pringsheim 

 in Berlin. Under the direction of these eminent men have, 

 within the last forty years, nearly all German universi- 

 ties established public botanical laboratories and physiolog- 

 ical institutes, whereby a school of , younger scientists was 

 brought up, who elaborated thus continuously and success- 

 fully, that there is presently hardly any one important plant 

 on which not the chain of development had link for link been 

 joined together to a closed 'ring. 



Furthermore had, during the same time, with equal and un- 

 abated zeal, the investigation of the development of the ani- 

 mal world been carried on, and we are now in a manner en- 

 abled to trace the evolution of the whole animated world, from 



