362 BOTANICAL GAZETTE [DECEMBER 
Aspidium Thelypteris—This species was studied in both bog 
and swampy mineral soil. The rhizomes were found to be always 
horizontal. The depth was 2-6 cm. in bog soil, and 1-6 cm. in min- 
eral soil. In no case were living parts found below water. The 
roots were almost horizontal when near the water table, but nearly 
vertical and going down to 15-17 cm. deep in a substratum that was 
only moist. No difference of any sort was apparent in peat and 
mineral soil. Fig. 1, which is a map of most of the rhizome 
Fic. 2.—Larix laricina with roots showing horizontal position; inset, young 
ieediing’ and Hpi three or four years old showing tap root becoming horizontal; 
maximum depth 6c 
system of one plant, shows that in the older parts there are numerous 
dead rhizome tips and few leaves, while in the younger parts the 
plant is vegetating very freely. The older parts were much dis- 
colored and too brittle to trace farther than is shown in the map. 
Larix laricina (fig. 2).—The larch had no tap root, all the roots 
being horizontal and above the water level, except where the 
weight of the tree forced them deeper into the peat. All living 
roots were 6 cm. or less in depth. There were only a few dozen 
comparat'vely young larches in the bog in question. No other 
tree species was found. 
