MODERN BIOLOGY 551 



when romantic idealism still prevailed in biological research-work. At that 

 time Goethe's spiral visions and metamorphosis theory were still playing 

 their part as foundations on which various naturalists based their concep- 

 tions of the form and growth of plants and the position and development 

 of their leaves. These imaginings produced appalling confusion in ideas and 

 theories. "It is remarkable," says Sachs in his Geschkhte der Botanik, "that 

 as soon as there was any mention of the metamorphosis of plants, even 

 gifted and clever men gave way to nonsensical gibberish." But even clear- 

 thinking investigators sought to solve these problems from a purely ideal 

 point of view; the position of the leaves of the plants was created by an 

 idea which expressed itself in mathematically formulated relations between 

 the leaves. Karl Friedrich Schimper (1803-67), for the greater part of his 

 life a private scholar, was one of these speculative plant-morphologists; he 

 expressed the "spiral tendency" in the position of the leaves by means of 

 a serial fraction. His ideas were further developed by Alexander Braun 

 (1805-77), who studied at Munich, among others under Schelling, and 

 finally became professor of botany at Berlin and a distinguished teacher. 

 Among his disciples was Haeckel, who highly admired him and was largely 

 influenced by him in the romantic direction. Braun, who was otherwise a 

 specialist of some merit, recorded his morphological speculations in a trea- 

 tise iJber die Verjiingung in der Nafur, a curious blend of exact knowledge and 

 romantic imaginative thought. The work contains a number of, for the time, 

 excellent studies of lower plants, especially unicellular Algas, the growth 

 and reproduction of which are carefully described. Upon these observations, 

 as well as some studies of the position of the leaves in buds and flowers and 

 on the stem of higher plants, is based a "living view of nature," which 

 tries to find in nature " nicht bloss die Wirkung toter Krafte, sondern den Aus- 

 druck lebendiger Tat.'' This conception of nature is based on "rejuvenation" 

 as the driving force in life, whereby the old is constantly being converted 

 into a new: the child's "old" milk-teeth into new ones, the "old" pupa 

 of the butterfly larvns into a new butterfly, to say nothing of the spring's 

 rejuvenation of leaves and herbs, which, of course, gave rise to the whole 

 of this speculation. "The spirit that develops in man is not outwardly united 

 to nature, for its appearance is already indicated in the lower stages of nat- 

 ural life, especially in the animal kingdom; rather the spiritual life is the 

 purest representation of the same basis of life as that which in previous stages 

 confronted us as natural life." This, of course, is pure natural philosophy; 

 it is no wonder, then, that Goethe's metamorphosis doctrine finds its appli- 

 cation here, both in ascending and descending metamorphosis and in the 

 spiral arrangement of the leaves, which on the model of Schimper is expressed 

 in mathematical formulas. It is strange to note how exact observations are 

 mixed up with this fantastic terminology, especially when it is applied to 



