106 KANSAS ACADEMY OF SCIENCE. 



basins are numerous; the drainage has not been completed. It is quite recently that 

 the glacier left there, as compared with Kansas. The Turtle mountains are, proba- 

 bly, the spot where the retreating glacier lingered longest. Its osars and kames 

 seem like the ridges of gravel described as on and about the southern edge of the 

 great Muir glacier, of Alaska. The phenomena are all new. In northeast Kansasi 

 the glacial phenomena are old, very old. Great morainic deposits, in Brown, Leaven- 

 worth and Douglas counties, are hidden by vegetation, which has covered the largest 

 bowlders, and the deposits of gravels and clays have been assorted and arranged, 

 and hills have been rounded to the angle of conservation. 



The loess which belongs to the newer ice age has overlapped parts of glaciated 

 Kansas; but there is an older loess that in places is very distinct, and the newer and 

 the older loess, in front of the retreating, ice-carried icebergs, great or small, which 

 accounts for a few glacial, subangular bowlders that have been found many miles 

 beyond the limits recognized above as those of the ice sheet. 



THE VARIABLE CHEMICAL COMPOSITION OF PLANTS AT DIFFERENT 

 SEASONS -ILLUSTRATED BY TARAXACUM DENS-LEONIS. 



BY PBOr. L. E. SATEE, UNIVEESITY OF KANSAS. 



It is perhaps a well-known fact that the soluble principles elaborated by plants 

 at different times during their growth differ very greatly, not only in quantity but 

 also markedly in quality. For example, the common persimmon contains during 

 the summer and until about frost a large percentage of a peculiar kind of tannin, 

 which becomes replaced about the time of frost by glucose, pectin, yellow coloring 

 matter, etc. Early in the spring, dandelion root contains uncrystallizable sugar, 

 which diminishes during the summer. In autumn, it abounds in that starchy prin- 

 ciple common to many of the roots of the natural order Compositaj, known by the 

 name of "inulin." Pectin is also present to a large extent. There is also a bitter 

 principle found in taraxacum root, called taraxacin, which makes it so valuable as a 

 medical agent. Finally, it contains a very small percentage of a peculiar acrid 

 principle soluble in alcoholic solutions. 



Some years ago the attention of pharmacologists was directed to the subject: 

 "The proper time for collection of dandelion root." Reviewing the literature, I 

 find many communications to the journals from the pens of very able men; but 

 these authorities differ as to the proper season for its collection and preparation 

 for medicinal use, and, so far as I am able to learn, it is now a somewhat unsettled 

 question. Very different seasons of the year are now recommended as the proper 

 time for gathering. One authority recommends the beginning of spring, even be- 

 fore blooming; another, July, August, and September; another, that it should be 

 collected between September and February. It stands to reason that that season 

 of the year in which the bitter principle, taraxacin, is most abundant is the best 

 time for collecting and drying. It has therefore occurred to me that I might bring 

 forward this subject anew, and at different seasons of the year make such analyses 

 of the root as will show the proportion and total amount of the various principles 

 contained in the plant, making special note of the most important principle, tarax- 

 acin. 



As I have just begun a series of analyses of the same roots collected in May and 

 September, neither of these being fully completed, I shall be able to report only a 

 few results in connection with the subject. I may add, also, that as the exact 



