EDUARD SCHONPELD. 381 



conclusions reached as the result of an unusually long and profound 

 study. This work must be regarded as Naegeli's greatest contri- 

 bution to speculative science, worthy to be classed with the mas- 

 terpieces of the great writers on evolution. He maintains that 

 variation arises from internal, not external causes, and that the 

 transmission of hereditary characters dejiends not on the general 

 protoplasm, but on a limited and definite part of it, the idioplasm. 

 The enunciation of the general principle in the Abstammungslehre 

 is forcibly and even brilliantly stated, and Naegeli's presentation 

 of the subject has exerted and will continue to exert a marked in- 

 fluence on modern thought, although in some details he allows 

 himself to indulge in views which are too purely speculative, and 

 not borne out by the more exact microscopic work of a younger 

 generation of workers.* 



EDUARD SCHONFELD. 



Eduard Schonfeld was born on December 22, 1828, at Hild- 

 burghausen, Germany. The comprehensive activity of his mind 

 was early displayed in the course of his education, for he studied 

 architecture and chemistry before finally selecting astronomy as 

 his special field of work. His astronomical studies were begun at 

 the University of Marburg, and continued, in 1852 and later, at 

 Bonn, under the guidance of the illustrious Argelander. He took 

 his degree in 1854, but had already in the previous year been 

 appointed Assistant in the Observatory. 



At this time, Argelander was entering upon the execution of 

 his plan for the formation of a catalogue which should exhibit the 

 approximate positions, and also the magnitudes, of all stars in the 

 northern hemisphere not fainter than the ninth magnitude. He 

 had made some preliminary observations for tliis purpose in 1852, 

 but the work was definitely begun only after he had been joined 

 by Schonfeld, who took a prominent part both in the observations 

 themselves and in their reduction. The catalogue itself, which 

 comprises 324,198 stars, was mainly drawn up by him. 



In 1859, Schonfeld was appointei Director of the Observatory 

 at Mannheim. Here he undertook the systematic observation of 

 variable stars, and his two successive catalogues of these objects 



* A detailed account of Naegeli's life and work is to be found in the " Neue 

 Zurcher Zeitung" for May 16, 1891, and in " Nature" for October 15, 1891. 



