The southern part of Alberta is covered by a short grass, very nutritive, but drying up in the middle of summer until the whole prairie is brown and unattractive.
But in the 13th century it began to fail, and in 1591 the drying up of the Papireto caused the extinction of the plant in that district.
With the drying up of this channel and the closing of Sandwich harbour in the 16th century, the present marshlands or level to the south and west of the isle were left.
In any case, the alterations in level appear to be merely periodic, and due to fluctuations in rainfall, and do not point, as some have supposed, to a secular drying up of the lake.
Not only was he the first discoverer of the rotifers, but he showed "how wonderfully nature has provided for the preservation of their species," by their tolerance of the drying-up of the water they inhabit, and the resistance afforded to the evaporation of the fluids of their bodies by the impermeability of the casing in which they then become enclosed.
