ONTOGENY OF LARVAL COLOR PATTERNS. 



H3 



ical colors are rare and chemico-physical of no great importance. The color 

 patterns, therefore, are largely pigmental, although to these may be added a 

 few instances of the specialized categories of color in the more specialized 

 species. As far as the colors themselves are concerned this genus exhibits a 

 full development of pigmental coloration, with the earliest stage in the devel- 

 opment of the more highly specialized physical and chemico-physical. 



THE ONTOGENY OF COLOR AND COLOR PATTERNS. 



IN THE LARV^. 



The ontogeny of larval or youthful ornamentation in animals has received 

 little attention from zoologists, although most interesting, suggestive, and con- 

 clusive data may be obtained from this source. Paleontologists, especially 

 Hyatt and his pupils, have obtained some notable results from their studies 

 along this line on fossil organisms. 



I have shown in a former paper that the color patterns of insects are of 

 segmental origin and that the various spots and stripes are in all probability 



E- o 

 o * 



ftu . 



a> 



"OCM 



s 



* a Z 



fee 



posterior prouotal band 

 anterior pronotal band 



anterior and posterior 

 bands of tergal spots 

 upon abdominal 

 segments 



posterior lateral epicranial^ 



anterior lateral epicranial.. 

 antenna ry 

 gular, 



,'protboracie spiracolat 



j-4- i-iii. ' uner tergals 



|i " middle tergals 

 Uj- .outer tergals 

 _ Ruiracuta spots 

 ,_baso-pleural 

 outer steraals 

 " middle Hterrmts 



Bpiraeulaf, l to 7 baBO-plcurnl (abd) 

 "metathoracic wing spot 

 mesothoracic wing spot 



baso-plcural (thoracic) 



Text-figure 7. Diagrammatic representation of the centers of color development 

 found in the young larvse of Leptinotarsas. Drawn from a young larva of L. unde- 

 cimtineata t aa seen in side view. 



directly derived from modified or combined, segmentally placed centers. In 

 Lepiinotarsa this idea has been put to a most exact test with the result, as will 

 appear in the following pages, that it appears to be in all respects valid. 



In the young larvae of very many Chrysomelidse, Coccinellidae, Cassidae, and 

 other forms is found a system of color centers which is highly suggestive and, 

 as we shall see later, ideal in its simplicity. In late embryos or newly hatched 



