430 PACKARD— ORIGIN OF MARKINGS OF ORGANISMS. [Dec. 2, 



Thus Irmscher^ states than on setting free a large number of com- 

 mon Noctuids (species of Agrotis and Leucania) most of them were 

 eaten by the redstart resting near by. But it was remarkable that 

 of the numerous Vanessa io which he set free, not a single one was 

 caught by the redstarts. 



Dr. A. Seitz'^ records having seen Pieris make a rush after the 

 feathers of birds and bits of paper which had fluttered down in the 

 air. He saw a young wagtail pursue a Colias hyale ; it rushed after 

 the butterfly, which fell to the ground, but the bird then flew at least 

 four or five times over the prostrate butterfly without taking any 

 further notice of it whatever. From this observation he infers that 

 the insectivorous birds in Europe are indifl"erent to or disdain butter- 

 flies, and he goes on to theoretically prove that butterflies are not 

 molested by birds. Undoubtedly the irregular wavering flight of 

 butterflies enables them to escape the occasional onset of birds. 

 Thus Seitz states from his observations that the kind of flight of 

 Lepidoptera has a good deal to do with the matter. The males of 

 several species of moths {e.g., Gastropacha quercus) whose flight is 

 irregular, restless and fluttering, are not followed by birds, which 

 will devour the females whose flight is more steady. 



12. Sokolowsky's Views on the Origin of the Markings of 

 Mammals and the Formation of Spots from 

 Longitudinal Stripes. 

 In his interesting paper Sokolowsky^ has been the first to thor- 

 oughly discuss the markings of mammals. He contends that the 

 most primitive style of markings are longitudinal stripes developed 

 in small ground mammals, and caused by the long, slender shadows 

 of the fern vegetations of the ground-zone of the primitive forests. 

 In the larger animals of the bush-zone there appeared a change of 

 markings, due to the play of light and shadow in the plants of this 

 zone. Such are Centetes, Geomys, Tamias or the chipmunk. In 

 Ccelogenys paca the five rows of round white spots on each side are 

 due to the breaking up of the originally five stripes into spots. The 

 greater variety of plants in the bush-zone formed a chaos of contrast- 

 ing light and shade, so that the markings of these or similar mammals 



1 Illust. Zeit. Ent. Neudamm.^ V, p. 75, Marz, I900. 



2 Spengel's Zool. Jahrbilcher, iii. 



3 Uber die Beziehungen zwischen Lebensweise und Zeichnung bei Saugetieren 

 Zurich, 1895. 



