234 Prof. K. F. H. Marx's Memoir of the Life and 



prosecute investigations for himself, now sixty years ago, more 

 comprehensive results than he attained have heen acquired, 

 yet it can with truth be affirmed that his conclusions, though 

 no doubt extended and occasionally corrected, have been in 

 no degree overturned. 



On the 9th May 1778, observations on green hydrae, then 

 in the act of reproduction, first led him to the perception 

 and subsequent extensive investigation of the incessantly active 

 power of nature. In tbe year 1780 appeared his treatise " On 

 the Forming Impulse (Bildungstrieb), and its Influence on 

 Generation and Reproduction, 11 * and, the year after, the mo- 

 nograph t " On the Forming Impulse and the Process of Gene- 

 ration." At that time he also wrote a paper " On an unusu- 

 ally simple kind of Propagation, "J which was that of the con- 

 ferva occurring in wells, whose mode of propagation he had 

 discovered on the 18th February 1781. 



He sent a short answer to the question proposed by the 

 Petersburg Academy, " On the power of Nutrition," || on the 

 25th May, the day after he finished it ; and obtained half the 

 prize. He wrote remarks on Troja's investigations regarding 

 the production of new bones. § Respecting the " Regenerat- 

 ing of an eye in the Water Salamander," he communicated 

 to a meeting of this society,^ the fact of four-fifths of the eye- 

 ball having been cut out, and a new eye having been formed. 



With great acuteness, and with rare knowledge, he pointed 

 out the anomalous** and diseased deviations of the forming 

 impulse (Bildungstrieb), and shewed how artificial means,tt or 



* Getting. Magaz. 1780. P. 247-2GG. 



t 1781. And then in the Comment, vol. viii. p. 41-G8 : De Nisu Formativo 

 ct Generationis Negotio, 1785. 



% Gutting. Magaz. 1781. No. i. p. 80-89. 



|| De Nutritione ultra vasa. The prize was adjudged on the 4th Decem- 

 ber 1788. The number of essays transmitted was twenty-four. Nova Acta, 

 Ac. Sc. Petropolit. v. 6. 1700. Histoire. Compare two treatises by K. F. 

 Wolf, St Petersburg, 1789 (the second is by C. F. Bom). 



§ Eichter's Chir. Bibliothek. Vol. vi. No. 1, 1782, p. 107. 



«[ Gott. gel. Anz. 1785. Part 47, p. 4G5. 



**Dc anomalis et vitiosis quibusdam nisus formativi aberrationis, 1812. 

 Commentat. recent, vol. ii. p. 3-20. 



tt Magazin fur das Neuestc aus der Physik, 1789. Vol. vi. part 1, p. 13. 



