xxx Trans. Acad. Set. of St. Louis. 



in the water crystallize upon the metallic hydrate formed by 

 the action of the lime on the metallic salt first added. 

 Aggregations of suspended matter soon appear and settle 

 rapidly, leaving the water clear and pure without any process 

 of filtration. 



May 1, 1905. 



President A. Alt in the chair; attendance sixteen. 



Mr. Louis Schmidt was elected an active member. 



Dr. N. M. Glatfelter presented by title a catalogue of 469 

 of the Higher Fungi in the vicinity of St. Louis. He exhib- 

 ited a number of interesting specimens, most of which were 

 new species and edible. 



Mr. G. Pauls presented some specimens of tulips which 

 had developed and colored their petals four inches under the 

 surface. 



Mr. Henri Th. A. Hus of the Missouri Botanical Garden 

 delivered a lecture on the " Influence of Man on the Form 

 of Plants," illustrated with green and herbarium specimens. 



The speaker introduced his subject by giving a short sketch 

 of the conditions necessitating, in course of time, the changes 

 in plants, made by man, because of his change from a bar- 

 barian to a civilized being. 



Under the influence of man the form of fruits and flowers, 

 and even entire plants, undergo changes, which may be in 

 the individual or in the species. Changes in the individual 

 are mechanical, based chiefly upon physiological consider- 

 ation. 



Among the principal means of influencing individuals, are 



1. Pruning, with the object of producing better fruit, or 

 for decorative purposes, as the hedges of the old Italian 

 country places and the Japanese gardens. 



2. Grafting, which produces improved forms as a result of 

 selection. 



3. Forcing, for the mercantile value, as of strawberries and 

 lillies of the valley. This has its limitations, however, as a 

 certain period of rest is necessary for every plant. But this 

 period of rest can be brought about earlier by not watering, 



