LIFE OF THE ENTIRE PLANT. 459 



Our present business is tlie observation of the physico-chemical processes 

 us they are found in the individual elementary organs, or in the groups of 

 the same, called tissue. What has been already said in the First Book will 

 hold good here also ; and we have now to consider how sometimes, through 

 the process of formation in the entire plant, special modifications appear 

 in the sum of the phenomena of the life of individual cells. These are, 

 however, but little known to us. Heat and light, which are essential to 

 many chemical operations, appear to act upon the entire plant in no other 

 way than upon the sum of the cells. The influence of electricity and 

 magnetism upon the cells is as little known to us as is the operation of 

 these agents upon the entire plant ; notwithstanding, electricity appears to 

 play an important part. On this subject there are some vague observa- 

 tions in Froriep's Notizen (vol. xix., No. 9., Aug. 1841.), by Thomas Pine. 

 Instead of indulging in conjectural fancies, I will here propound some 

 queries, which will not appear idle since they require solution. Does a 

 tree in which vegetation is vigorous, or yet better a vegetating Musa, or 

 the same in tropical climates, exercise any influence upon a magnet sus- 

 pended near it ? If a Chara were made to grow so that it should be 

 spirally surrounded by a continuous galvanic stream, which should be 

 either parallel or at right angles with the direction of the ascent of the 

 sap, would it suffer any change in its vegetation, and what ? 



The dependance of the life of the plant upon the life of the earth is in 

 the highest degree interesting. We must here assume, that in the 

 agencies on which the meteorological phenomena, the formative principle 

 in the embryo, &c., depend, is to be found the cause why, at the blooming 

 time of a particular plant, a particular kind of insect is produced, whose 

 life again depends upon the nectar in the flower of the plant, and by the 

 sucking up of which the transference of the pollen to the stigma is 

 effected. For particular plants other agencies are needed; as, for 

 example, it is requisite that wind should occur at the flowering time of 

 the Abietinece, that there should be undulatory motion of the water at the 

 time of the flowering of the Vallisneria, and rain with the development 

 of the capsules of Ambrosinia Bassi. These phenomena may appear 

 accidental, but they are necessary consequences of the primary powers 

 which are seen in the formative processes of the earth. The rain could 

 not fall at the appointed time, and under the existing circumstances, 

 without at the same time causing the internal formative energy of the 

 earth to bring forth an Ambrosinia ; and the meteorological relations 

 would at the same time be so arranged, that on the developed spathe rain 

 should fall. The spathe of the Ambrosinia is boat-shaped, and floats upon 

 the water. By means of the capsule, whose wing-formed appendages, 

 uniting with the spathe, form a little cavity, the spathe is divided into an 

 upper and under chamber. In the upper one is found one single ovary, 

 in the under one exclusively the anthers. The pollen cannot reach the 

 stigma without the assistance of rain, which filling the under chamber 

 and the half of the upper one, lifts the floating pollen to the level of the 

 stigma, and hence the pollen-tubes can pass along. This may be taken 

 as one of the least known examples of the dependance of plants upon the 

 assistance of external natural phenomena. The operations of wind and 

 weather are more generally known, as also is the aid rendered by insects, 

 on which subject we find some interesting observations by Conrad 

 Sprengel, on the Secrets of Nature discovered in the Structure and Im- 

 pregnation of Flowers ; Berlin, 1793. 



