Page:Aurora Australis.djvu/177

LIFE UNDER DIFFICULTIES. species (Adineta Grandis) produces living young, being an exception in this respect in the genus. The life both of parent and young may apparently be arrested at any stage. Animals bearing from one to seven young may be seen, some well developed, some at a very early stage. This species is further remarkable as living in water so saline as to be a sort of brine.

Whether the same species which endure great cold can also endure great heat, can only be settled by experiment. All the species found at Cape Royds have been brought quickly from -30° Fahr. to +60° Fahr., and have then been found actively feeding.

Some of the rotifers found at Cape Royds are supposed to be species widely distributed over the world. Others are peculiar, and unknown as yet any where else, and one is of a very peculiar form.

Portraits of some of these Cape Royds natives are shown on the plate, highly magnified.

From the instances given above of kinds which can resist heat and drought, it will appear that the Bdelloid Rotifer is one of the hardiest creatures in the world. It promises now to shed much light on the limits of temperature at which life is possible on the earth.

J. MURRAY.