122 Lake Maxinkuckee, Physical and Biological Survey 



ized and set seed, the pistillate flower extending on a long peduncle 

 to the surface of the water and the staminate blossom breaking off 

 and floating away. Moreover, where conditions are so favorable 

 for vegetative propagation one might naturally expect this to be 

 a common mode. And so it proves to be; nearly all the aquatics 

 propagate freely by means of special buds or tubers. Some of 

 them, especially those of Potamogeton pectinattis, are of a remark- 

 able character. 



The peculiarities of the various species in regard to reproduc- 

 tion, method of dissemination, and distribution, will be taken up 

 under each species. A few general remarks may be made here, 

 however, concerning the behavior of the aquatic flora as a whole. 



In addition to bearing seeds, most of the aquatics propagate by 

 means of so-called winter buds, which are merely fragments or bits 

 of branches sometimes more or less modified. The expression 

 "winter-bud" is hardly a happy one, as it serves to keep in mind 

 the notion that the aquatic plants need some special device for sur- 

 viving unfavorable seasons, and in that it increases the difficulty, 

 already great enough, of divesting our minds of the notion of severe 

 changes of season to which we are accustomed and for which the 

 land plants must provide, but which do not apply to the aquatics. 

 The propagation buds may be formed at almost any time of the 

 year during the growing season, many of them during August. 

 Every one is acquainted with the facility with which many of our 

 herbaceous plants, such as the geranium, purslane, wild morning 

 glory, etc., send out roots from cuttings, and how the presence of 

 water or moisture favors the formation of such roots, so that the 

 usual way to start some plants, such as the willow, oleander, etc., 

 is simply to place the end of a cutting in a vase or bottle of water. 

 Among the aquatics we have the herbaceous growth and the water 

 always present. A cause contributing to the formation and de- 

 tachment of "winter-buds" during the autumn months is that there 

 is then considerable wind and choppy weather so that the plants 

 are subjected to unusual stress and strain, and portions are easily 

 detached. The portions detached drift about hither and yon with 

 the various movements of the water. They rest during the period 

 when the lake is covered with ice, but are further disseminated and 

 scattered by the gales of early spring after the ice has melted. 



As a result of the more or less permanent nature of the plants 

 and plant-patches in the lake, and of the habit of detached portions 

 rooting and growing wherever they settle or the shifting currents 

 carry them, the locations of the old plant-patches do not change 

 much, but new patches spring up here and there. Such influences 



