PROCEEDINGS, 1915. 81 



Many of our insects have, like the skunk, the power of emitting an 

 odor most offensive to their enemies. Here we have a common carrion 

 beetle which is an insect having this power, and we find it conspicuously 

 marked with yellow. The common potato beetle, the lady-bugs and 

 many others are distasteful to most birds, and we find them advertising 

 their presence by conspicuous bright-colored bands or spots. 



Here again is another insect commonly called the "horn-tail" from 

 the form of the ovipositor. This ovipositor though for the purpose of de- 

 positing eggs beneath bark, can be used as a most effective weapon of de- 

 fense, and so that insectivorous birds and mammals may make no mistake 

 she is advertised by a bright orange abdomen and metallic wings and 

 thorax. For the same reason, our bees, wasps, ichneumon-flies, and other 

 insects, that possess such sharp means of defense, are most conspicuously 

 colored. It is generally known that our hairy caterpillars are distasteful 

 to most birds, so in them we find no attempt at concealment, many of our 

 tiger moths larvae being most glaring in their coloring. 



This brings us to one of the most startling and wonderful principles 

 in connection with the color of animals, — what is known as "protective 

 mimicry." I will ask you to note carefully this upper figure. It represents 

 the milkweed, or monarch butterfly, a wonderful insect in many ways. 

 This is one of the protected insects of which we were speaking a moment 

 ago. It is evidently distasteful to insect-eating birds, and is remarkable 

 for its leisurely drifting flight, and its high colouring. 



Now notice the lower figure. At first you see but little difference, but 

 a closer examination will show that the veining of the wings is quite dif- 

 ferent. In fact this butterfly, the "Viceroy" belongs to an entirely dif- 

 ferent genus, and what is more remarkable has no power of self-protec- 

 tion. But we see by imitating so closely the coloring of the protected 

 "monarch" it steals its thunder and so often avoids death. 



But here we have a much more startling case of mimicry. I will ask 

 you to notice for a moment just the two figures at the top of this plate. 

 This is our ordinary wasp, you have all, doubtless, at some time met her, 

 and you are quite prepared to understand that insect eating birds choose 

 to leave her in peace. You see that she is advertised by the usual bright 

 colors of protected insects. Now this other figure is not a wasp at 

 all, and is about as nearly related to a wasp as a sheep is to a wolf. This 

 is really a moth, a creature without defense. But notice how in coloring 

 and form it resembles our acquaintance the wasp. Notice too, that 

 even the wings have lost a good portion of the feathery scales common to 

 most moth's wings, leaving them nearly transparent, the better to imi- 

 tate the wings of a wasp. Now, though absolutely weaponless, this little 

 moth secures a great deal of protection from its close resemblance to the 



