244 BIOLOGY AND ITS MAKERS 



ratory and examined the sections of the dorsal cord, the par- 

 ticular structure upon which Schwann had been working. 

 Schleiden at once recognized the nuclei in this structure as 

 being similar to those which he had observed in plants, and 

 thus aided Schwann to come to the conclusion that the ele- 

 ments in animal tissues were practically identical with those in 

 plant tissues. 



Schwann. The personalities of the co-founders of the 

 cell-theory are interesting. Schwann was a man of gentle, 

 pacific disposition, who avoided all controversies aroused by 

 his many scientific discoveries. In his portrait (Fig. 74) we see 

 a man whose striking qualities are good -will and benignity. 

 His friend Henle gives this description of him : "He was a man 

 of stature below the medium, with a beardless face, an almost 

 infantile and always smiling expression, smooth, dark-brown 

 hair, wearing a fur-trimmed dressing-gown, living in a poorly 

 lighted room on the second floor of a restaurant which was 

 not even of the second class. He would pass whole days 

 there without going out, with a few rare books around him, 

 and numerous glass vessels, retorts, vials, and tubes, simple 

 apparatus which he made himself. Or I go in imagina- 

 tion to the dark and fusty halls of the Anatomical Institute 

 where we used to work till nightfall by the side of our excellent 

 chief, Johann M tiller. We took our dinner in the evening, 

 after the English fashion, so that we might enjoy more of the 

 advantages of daylight." 



Schwann drew part of his stimulus from his great master, 

 Johannes Miiller. He was associated with him as a student, 

 first in the University of Wiirzburg, where M tiller, with rare 

 discernment for recognizing genius, selected Schwann for 

 especial favors and for close personal friendship. The influ- 

 ence of his long association with Mtiller, the greatest of all 

 trainers of anatomists and physiologists of the nineteenth 

 century, must have been very uplifting. A few years later, 



