422 Reviews. — Address by J. E. Tcscliemacher. 



they must throw much liijht on tlie functions of different parts, as 

 well as on che relations these parts hear to each other. Every devi- 

 ation from regular structure, called by the man of science abnormal, 

 must afford insight into the laws of that structure; and I am con- 

 vinced that the more these changes are studied by the scientific bot- 

 anist, the more enlightened will become the views on those portions 

 of the vegetable kingdom which are now comparatively obscure. 



Mr. Tescheinacher next offers some views upon the nec- 

 tariferous organs of flowers, and their importance in the econ- 

 omy of vegetation, relating an experiment, which has a direct 

 bearing upon the subject of guano. 



The nectariferous juices, or, as it is commonly called, the honey 

 in flowers, is usually separated or secreted by glandular boilies call- 

 ed nectaries, and this honey has by many been supposed to be of in- 

 disi)ensable service in the fecundation of the seed; but there are also 

 glands on the leaves and leafstalks, (petioles) of many plants, which 

 perform the same office of secreting honey: here, of course, it can- 

 not be of use for this purpose. Such glands exist on the petioles, or 

 leaf stalks, of most of the acacia tribe, on the tips of three or four 

 of the lower serratures on the leaves of Grevvia, on various parts 

 of the leaves or stems of the balsam, on passiflora, and many 

 other plants. These glands only secrete honey during the youth and 

 growth of the leaf; it is then only that their operation and beautiful 

 structure can be j)roperly observed; when the leaf has attained its 

 full growth and perfection, the active part of these glands dries up, 

 the time for observing their powers is past, and the leaf then pro- 

 ceeds in its own important function of elaborating the sap. It has 

 been lately surmised, and it appears to me with every probability of 

 truth, that this honey is an excretion thrown off, of the superabundant 

 and useless part of the juices, after the leaf or flower has selected all 

 that is necessary, precisely analogous to the excretions of the animal 

 frame. I will attempt, very briefly, to show that this view, if cor- 

 rect, is of some importance, both to agriculture and horticulture. 

 Mr. A. A. Hayes, of Roxbury, in a beautiful, simple, and I believe 

 original experiment, exhibited before the Chemical Society of Boston 

 this spring, proved the existence of phosphoric acid (probably com- 

 bined in several seeds,) by immersing sections of them in weak solu- 



tions of sulphate or acetate of copper; in whatever part of the seed 

 phosphoric acid existed, on that part was deposited a precipitate of 

 phosphate of copper; — this was |)articularly evident in the seeds of 

 Indian corn. 



A certain quantity of phosphoric acid, or phosphates, is therefore 

 necessary to the existence of these seeds; and that ))art of the plant, 

 (probably the flower,) destined to perform the function of preparing 

 the juices for these seeds, must go on exerting its utmost powers in 

 selecting and rejecting until the requisite quantity of phosjihates and 

 other ingredients for the seed are obtained. Now the phos()hates in 

 most soils exist in extremely minute quantifies; therefore, those 

 plants and flowers whose seeds require any quantity, must extract 

 large portions of food from the soil before they can select the amount 



