386 S. J. HOLMES 



it with the posterior pair of legs. Alpheus pachychirus St. has 

 the curious habit of forming a tube of an alga which grows in 

 the form of a sheet of threads. The Alpheus lies on its back, 

 draws the folds of the alga together on either side, then, by 

 pulling the threads through holes made by its feet, actually 

 sews together the folds of the alga to form a complete tube. 



By throwing light from various differently colored surfaces 

 on the daphnid Simocephalus, Erhard (16) noted that the eye 

 reacted in the same way as to changes in the intensity of any 

 one color. He concludes, like Hess, that daphnids are color 

 blind. 



The behavior of the parasitic copepod Lemaeopoda edwardsii 

 has been studied by Fasten (17) who finds that the free swim- 

 ming young habitually move in a spiral course, thus increasing 

 their opportunities of coming into contact with their host. 

 The larvae are positive even in strong light and swim near the 

 surface during the day, but sink toward the bottom at night. 

 Observations were made on thigmotaxis, geotaxis, reactions to 

 temperature changes, and to various chemicals, and also on the 

 method by which the larvae attach themselves to the gills of 

 their host, the trout. . 



According to Franz (18) phototaxis is either a device for 

 scattering the species, as when it occurs in the larvae of animals 

 inhabiting the bottom of waters, or in a movement of flight 

 (Fluchtbewegung) by which the animal escapes unfavorable or 

 threatening conditions. For the arguments supporting this 

 unique standpoint reference must be made to the original paper. 

 Franz (19) has also given a more or less popular account of the 

 behavior of snails. 



Frisch and Kupelweiser (20), from a series of experiments on 

 Daphnia and Artemia, conclude that these animals have the 

 power of distinguishing different colors. If Daphnias which 

 have become indifferent to a certain intensity of light are ex- 

 posed to a light of less intensity they become positive, whereas 

 if the intensity of light is increased they become negative. How- 

 ever, if one interposes a blue screen, the daphnids in spite of 

 the diminution of light intensity become negative. If one adds 

 yellow light to the white light to which Daphnids have become 

 indifferent there is evoked a positive reaction notwithstanding 



