HISTORICAL SKETCH 



England, France, and Germany. In less than two years after the 

 publication of this memoir and in spite of his lack of a proper 

 university training, the University of Rostock conferred upon 

 Hofmeister the degree of Doctor of Philosophy honoris causa, thereby 

 giving formal recognition to his high position as a scientific investi- 

 gator. A few of Hofmeister's illustrations of the embryo sac and 

 the relation between the pollen tube and the egg are presented in 

 Fig. 5. 



Schleiden and Schacht contin- 

 ued to hold their previous opin- 

 ion . Schacht brought out a large 

 monograph in 1850, with 26 plates 

 and a considerable number of 

 drawings. These were beauti- 

 fully executed, but in every case 

 he mistook the egg cell for the 

 tip of the pollen tube (Fig. 6) . In 

 conclusion he said: "The tend- 

 ency towards error is so inherent 

 in human nature that the work 

 of one's head, like that of his 

 hand, is never perfect, and con- 

 sequently I do not hold mine 

 to be free from error and mis- 

 conception, but I have tried to 

 minimize these as much as pos- 

 sible. ... In chief matter, i.e., 



the origin of the embryo from the pollen tube, no one can convince 

 me that there has been any mistake or misconception. . . . My 

 preparations are so conclusive on this point that I can confidently 

 look forward to answering any criticisms that may be directed 

 against it." The Imperial Institute of the Netherlands at Am- 

 sterdam accepted Schacht's essay and awarded him a prize for its 

 production. 



However, the evidence against Schleiden and Schacht soon be- 

 came so overwhelming that eventually both of them had to retract 

 their opinions, and in 1856 Radlkofer published a comprehensive 

 review of the question accepting Hofmeister's conclusions in toto. 

 Schleiden soon gave up all botanical work and settled down in 

 Dresden as a private teacher of history and philosophy. 



Fig. 4. Wilhelm Hofmeister. 



