362 



SCIENCE. 



[N. S. Vol. V. No. 113. 



considered, and the origination of the deltas in 

 the sea was advocated. 



Mr. Grabau replied briefly to some of the 

 points raised in the discussion and emphasized 

 the differences between erosion slopes and con- 

 struction slopes ; the pointing of the slopes was 

 stated ; the material on the northern side of the 

 sand plains was perhaps coarser. 



Professor W. M. Davis defined briefly and 

 with graphic illustrations coastal plains, and 

 gave the outline for a geographic classification 

 of the same. He advocated the use of distinct- 

 ive descriptive names, and stated that the in- 

 troduction of such terms as doab and cuesta 

 would be of advantage to geographic science. 



Professor Shaler claimed that many of the 

 terms could be expressed by words in our own 

 language, and that the introduction of words 

 from foreign sources was to be deprecated. 

 Samuel Henshaw, 



Secretary. 



THE ACADEMY OF SCIENCE OP ST. LOUIS. 



At the meeting of the Academy of Science of 

 St. Louis on the evening of February 1, 1897, 

 Professor L. H. Pammel read a paper embody- 

 ing ecological notes on some Colorado plants, 

 observing that botanists who have studied the 

 Rocky Mountain flora have frequently com- 

 mented on the interest attached to the plants 

 from an ecological standpoint, but most per- 

 plexing to the systematist. It is not strange 

 that this should be the case, since there are 

 great differences in altitude and soil, and the 

 relative humidity of the air varies greatly. 

 This is a most prominent factor in the develop- 

 ment of plant life. A cursory glance at the 

 plains flora of eastern Colorado shows that there 

 are representatives of a flora common from 

 Texas to British America and east to Indiana. 

 We should not for a moment suppose that the 

 species are identical in structure, since the con- 

 ditions under which they occur are so differ- 

 ent. Attention was called to the great abun- 

 dance of plants disseminated by the wind, as 

 Cycloloma, Salsola, Solanum rostratum, Pop- 

 ulus, Cercocarpus, Tire-weeds' {Epilobium 

 apicatum and Arnica cordifolia), Hordeum ju- 

 batum, Elymus sitanion, etc. Plant migration 

 may be studied to better advantage in the irri- 



gated districts of the West than elsewhere, 

 partly because the water carries many seeds 

 and fruits in a mechanical way, and partly be- 

 cause the soil is very favorable for the develop- 

 ment of plants. Instances were cited where 

 several foreign weeds are becoming abundant, 

 as Tragopogon porrifolius and Lactuca Scariola. 

 The latter, known as an introduced plant for 

 more than a quarter of a century, is common at 

 an altitude of 7,500 feet in Clear Creek Canon. 

 Once having become acclimated, it is easy to 

 see how Prickly Lettuce is widely disseminated. 



Collectors appreciate the great importance of 

 giving more attention to conditions under 

 which plants thrive, such as phases of develop- 

 ment, soil, climate and altitudinal distribution. 

 Structures of plants are produced to meet cer- 

 tain conditions. Under extreme conditions 

 protective devices are more pronounced. In 

 discussing some of the plants. Warming's 

 classification into Hydrophytes, Xerophytes, 

 Halophytes and Mesophytes was adopted. 

 The Mesophytes of eastern Iowa were compared 

 with some of the Xerophytes of western Iowa, 

 such as Yucca angustifolia, Mentzelia ornata, 

 Liatris punctata, etc. These increase in abun- 

 dance in western Nebraska, and attain a maxi- 

 mum development in northern Colorado. In 

 the foot-hills and mountains the Mesophytes 

 constitute a large class, although the Xero- 

 phytes are common in dry, open, sunny places. 

 The photosynthetic system is reduced to guard 

 against excessive transpiration which would 

 otherwise take place at high altitudes. The 

 thick rootstock of alpine plants in dry open 

 places is an admirable protection against drouth 

 and cold. In canons where snow remains on 

 the ground plants do not need this protection. 

 Halophytes are not numerous in species and 

 genera. Hydrophytes are abundant at higher 

 altitudes, where they occur in marshes and 

 along streams. 



At the meeting of the Academy of Science, 

 of St. Louis, on the evening of February 15, 

 1897, Professor J. H. Kinealy presented a pre- 

 liminary discussion of the Poley air-lift pump, 

 a device for pumping water from artesian wells 

 by injecting into the pump tube, at a consider- 

 able depth below the surface of the water, 

 bubbles of air from an air compressor. 



