Meyen's Report for 1839 on Physiological Botany. 167 



gamous plants. His researches on the stigma are by no 

 means favourable to the theory of M. Endlicher, according 

 to which the moisture of the stigma is the fertilizing sub- 

 stance; and he moreover states, that there is just as little 

 foundation for the theory of M. Schleiden, according to 

 which the embryo-sac effects the fertilization. M. Unger 

 gives the question quite another direction, and one which, as 

 he believes, corresponds better with the nature of the sub- 

 ject. He says : What important objection could be made to 

 the supposition, that the pollen grains, when they arrive on 

 the stigma, are already fecundated ? Does not analogy lead 

 us to suppose that their formation is a work of fertilization ? 

 In this case, the male organs of plants must be sought in the 

 anthers or the neighbouring parts, etc. M. Bernhardi^ 

 has expressed new doubts concerning the general idea, that 

 the formation of the seed, in Phanerogamic plants, depends 

 solely and alone upon sexual contact ; he brings forward 

 observations which are unfavourable both to the old and the 

 new theory of fecundation. Bernhardi calls the followers of 

 the old theory the Animalculists, and those of the new, who 

 seek the germ of the future plant in the contents of the 

 pollen, the Pollenists. Against the doctrines of the Pollen- 

 ists he brings forward the observations of Gaertner, namely, 

 that many seed-bearing hybrids, by being continually grown 

 from seeds, return into the primitive form ; for this can- 

 not be otherwise explained than by the assumption that in 

 this case the female parent had a greater share in the for- 

 mation of the embryo than the male. The only means of 

 escape left for the Pollenists, is to ask whether these observa- 

 tions are quite correct or not. The most important part of 

 M. Bernhardi's work, however, treats of the observations, 

 according to which seeds perfectly capable of germinating 

 have been formed in the ovaries of several plants without 

 previous contact wdth pollen ; in this case, therefore, the 

 female alone was sufficient for the formation of the seeds : 

 the observations of different botanists are here mentioned, and 

 moreover, in order to render such a production less incredi- 

 ble, many statements — according to which animals, as insects, 

 salamanders, etc., have produced young without previous 

 fecundation — are brought forward. The numerous experi- 

 ments which M. Bernhardi has made with all possible care 

 with the hemp plants, and their results, are circumstantially 

 described. In April 1811 he sowed thirty seeds, and ob- 

 tained twenty-one plants, nine male, twelve female. From 



* Ueber Biltlung von Saumen ohne vorhergegangne Befruchtung. — 

 Oito's und Dietrich's Allgemeine Gartenzeitung 1839, No. 41, 42. 



