Lake Maxinkuckee, Physical and Biological Survey 171 



This plant propagates by means of buds which are often formed 

 as early as the middle of July, and are found from then on through 

 the winter. They appear to be formed in the axils of the leaves. 

 They are the shape of a closed fan, the thick flat leaves (quite un- 

 like the thin wavy vegetative leaves) being packed full of reserve 

 food material and closely pressed together. During the winter the 

 plants also put out abundant roots just a little behind the apex and 

 these may detach themselves and produce new plants. 



14. LARGE-LEAVED PONDWEED 



POTAMOGETON AMPLIFOLIUS Tuckerman 



This is one of the most attractive species of plants in the lake, 

 the large, gracefully curved delicate green leaves showing up 

 through the water very handsomely. It prefers rich mucky soil 

 and water of moderate depth. It is rarely found in water less 

 than 6 feet deep and is most abundant in water from 8 to 12 feet. 

 It has been dredged in water 24 feet deep. In shallow water it has 

 oval smooth floating leaves quite unlike the thin and wavy sub- 

 mersed ones and much like the floating leaves of P. natans to which 

 it is closely related. In deep water there are no special floating 

 leaves. Good-sized patches are common near the Ice-houses, and 

 throughout Outlet Bay. It is also found in abundance at the Weed- 

 patch and there is a large fine patch in the neighborhood of Norris 

 Inlet. There is another large patch ofl" from the green boat-house 

 in the Inlet region, but there is none along the east side. Chara 

 and some of the less conspicuous species of pondweed, such as P. 

 pectinatiis, often grow intermixed with it. Where it grows very 

 densely, however, it conceals or excludes other species. 



15. TAPE-GRASS; EEL-GRASS 



VALLISNERIA SPIRALIS Linnicus 



Rather abundant and apparently considerably on the increase. 

 It grows scattered over the bottom at various depths. It has been 

 dredged at a depth of 24 feet, and from this depth it extends almost 

 to the water's edge in suitable places. Dr. Scovell has made the 

 interesting observation that the plants bearing the pistillate flowers 

 grow in shallow water, none of them having been observed in water 

 at a greater depth than 2 or 3 feet, while the staminate plants were 

 most abundant in water from 8 to 18 feet. The higher plants are 

 pf course only indirectly sexual, but this observation suggests ex- 

 periments along the line of planting seed of Vallisneria at different 

 depths and observing the effect of depth of water in sex-determina- 



