PHYSIOLOGICAL BOTANY. 



285 



Corolla. Castration has no effect upon the corolla, and 

 the presence of the stamens is not in the least necessary 

 for the preservation of its integrity and perfect develop- 

 ment. The styles are generally developed subsequently 

 to the corolla, in a few plants only does the reverse occur, 

 as in Lychnis diurna, vespertina, Dianthus barbatus and 

 superbus. When in the latter case the stigmas are sprinkled 

 with the pollen of the same plant, whilst the flower is but 

 little or only half developed, the growth of the latter is 

 checked, or entirely ceases. Many observations and ex- 

 periments are made upon the diurnal sleep of plants; 

 impregnation exerts great influence upon it. 4. Upon 

 the secretion of honey (nectar) in flower. Tending rather 

 to contradict the views which have been asserted, than to 

 propose definite laws. 5. Upon the stamens of plants. 

 The observation is remarkable, that hybridation gives a 

 tendency to wasting of the anthers. The duration of 

 the power of the pollen is very different in different plants, 

 and also very different from the duration of the suscepti- 

 bility of the female organ to impregnation. The author's 

 remarks upon the pollen-tubes, and their penetration into 

 the micropyle, do not bear the least relation to the rest. 

 6. On the evolution of heat from flowers. Many original 

 observations. It occurs also in the female organs, and 

 is often connected with the odour. 7. On the pistil. 

 8. On the phenomena of irritability and motion in the 

 flowers and organs of fructification of plants. A number 

 of observations and experiments, especially upon the irri- 

 tability of the pistil in Mimulus. Development of the same. 

 When cut off and kept in moist sand, they exhibited 

 the same phenomena as when in situ, the destruction of 

 the one stigma exerts no particular influence, concussion 

 produces no effect upon them. Experiments with che- 

 mical irritants. Among these there are also experiments 

 with oil of morphia (a mixture of morphia and poppy- oil), 

 which prove, that the irritability and capability of move- 

 ment of the pistil of Mimulus is diminished and finally 

 destroyed by it. This is also the case with Strychnine 



