92 A NATURALIST IN THE GREAT LAKES REGION 



animals locally. Thus we have a distinct spring flora. Note, 

 for instance, the early annuals of the oak woods spring 

 beauties, anemone, toothwort, trillium, hepatica, Dutchman's- 

 breeches, dogtooth violet, bloodroot these and others like them 

 are all plants that are up and in blossom before the trees are in 

 leaf to shade them (Fig. 55). They get through with their life- 

 cycle bud and flower and fruit here on the forest floor while 

 the great trees overhead are just beginning to stir with the thrill 

 of the spring awakening. These plants have found an unoccupied 

 part of the season, and they make the best of it. They all 

 possess underground stems loaded with stored food that enable 

 them to make this very rapid growth, then slowly accumulate 

 during months of shade a supply sufficient for the next spring. 

 Moreover, in many cases their tender leaves that appear while 

 frosts are still common are clothed in dense hair a veritable 

 fur coat to protect them. They are replaced later by other 

 plants that have become adjusted to growing in the dense 

 shade of the summer under the trees. Those mentioned need 

 abundant sunlight to carry through their brief program of rapid 

 maturation. 



The temporary grassy ponds that result from the melting 

 of the snows are the homes of a group of animals that appear 

 marvelously indifferent to the low temperatures of early spring; 

 they thrive in the ice-rimmed water. There is the so-called 

 fairy shrimp, Eubranchipus (Fig. 56^), not a shrimp at all, though 

 its airy grace and mysterious appearance make the rest of the 

 name appropriate enough. It is a reddish-brown crustacean, 

 a quarter of an inch long when first seen, but growing rapidly 

 to an inch in length. It swims on its back, waving nineteen 

 pairs of feathery legs to propel itself. The head bears a pair of 

 staring compound eyes. The egg sacks of the females are con- 

 spicuous early, and strings of slender eggs can be seen in the 

 semi-transparent body on their way to be discharged into the 

 icy water. The adults soon die; the whole life-history occupies 

 only a month or so of early spring. The eggs lie dormant in 



