ADAPTATION IN COLORATION. 217 



Other species of the genus also possess the same combination of characters. 

 Thus, lacerata, the largest species in the genus, is a conspicuous object on 

 account of its black and white color. Like undecimlineata, it lives exposed 

 upon the upper side of the leaves of the topmost branches of its food plant, 

 where it is most liable to attack. On the green leaf in the bright tropical sun- 

 shine its black and white pattern is conspicuous, even at a distance of 50. to 75 

 feet, and could not fail to be observed by the keen-eyed insectivorous birds 

 and lizards ; yet, in spite of its coloration and position, I have never seen it 

 attacked, nor have I ever found mutilated specimens. 



The adults of L. rubiginosa are of a uniform bright red color, and as they 

 are large the red color it makes upon the green leaves of its food plant may 

 be seen with ease from a considerable distance. Other species of the genus 

 are also conspicuously colored — violescens and lihatrix, with their brilliant 

 metallic blue-green colors, and dilecta and its allies, and many others — and 

 they all rest in exposed positions. 



The species multitceniata, oblongata, melanothorax , rubicunda, and decern- 

 lineata have a conspicuous color pattern of yellow and black or red and black, 

 and are quite as well protected from their enemies as are those with white and 

 black. During the years of the dissemination of decemlineata numerous 

 experiments were made to discover whether domestic fowls — ducks, geese, and 

 turkeys — would eat the intruders. The universal observation was that decem- 

 lineata was eaten sparingly, if at all, and then mostly by young birds. One 

 ingenuous experimenter in Massachusetts inclosed fowls in a yard without 

 other food than these beetles, and announced with great satisfaction the fact 

 that after som.e days the beetles "were eaten with great relish." It would be 

 interesting to know whether the same might not have been recorded of the 

 experimenter himself under similar conditions. Various birds, orioles, gros- 

 beaks, cuckoos, etc., have been observed by others to attack this beetle, and the 

 "bob white" eats potato bugs freely (vide Yearbook U. S. Dept. Agr., 1903) ; 

 also, they have been found in the stomachs of a considerable number of species, 

 but there is little, if any, evidence to indicate whether these birds were young 

 or whether they were experienced. I have also frequently seen decemlineata 

 in nature picked up by orioles, blackbirds, catbirds, robins, grosbeaks, and 

 other birds, and then dropped without being crushed or eaten. 



L. decemlineata has on the elytra and around the edge of the thorax closely 

 set rows of compound glands which secrete an oily, bad-tasting and bad- 

 smelling fluid. If one of these beetles be picked up between the thumb and 

 forefinger gently, and the elytra examined under a hand lens, no secretion will 

 be found, but if ever so gentle a pressure be exerted upon the beetle, and the 

 elytron watched under a hand lens, minute drops of the yellow, oily liquid will 

 be seen to be suddenly extruded from each of the numerous glands. When a 

 bird picks up one of these beetles and exerts pressure upon it with either beak 

 or tongue, the result is an immediate extrusion of the repugnatorial fluid, in 



