THE STATE ENTOMOLOGIST. 13 



fragrans, shows how in that species the "scale" is not formed of 

 the lifeless body of the female, but is a distinct integument, con- 

 structed by the female to protect herself and her eggs, and probably 

 secreted from the general surface of the body. 



However, I believe that the entomologist will have about as diffi- 

 cult a task to ascertain its real mode of growth as would the physiolo- 

 gist to learn how the flesh on your fingers acquires its natural form. 

 We might with equal reason try to learn why and how the thousand 

 different excrescences and galls caused by insects are formed ! Why 

 is it that the larva hatching from an egg deposited on a rose leaf by 

 a little four-winged fly, the Rhodites ignota of Osten Sacken, causes 

 a peculiar growth or gall in the form of a mangel-wurzel, or beet seed 

 to surround it, while that of a similar fly, belonging to the very same 

 genus — the Rhodites radicum of Osten Sacken — hatched from eggs 

 deposited in the root of the same plant, causes an entirely different 

 gall? Why is it that the puncture of a little yellow louse, Pemphi- 

 gus (?) vitifolice, Fitch (or as Henry Shimer, of Mt. Carroll, would 

 have it, Daktylosphcera vitifolice), by puncturing a grape leaf, causes 

 an unnatural growth to surround and entomb it in the shape of the little 

 green globular galls of different sizes,so common on Clinton grape vines, 

 while the same sized puncture of another louse (Aphis vitis, Scopoli) 

 produces no such effect? Why, again, does a little Lepidopterous 

 larva, often found in the golden rod (the larva of Oelechia gallcesoli- 

 daginis, described in a future chapter of this report), produce an 

 elongated hollow gall, while a Dipterous larva (Trypeta solidaginis, 

 Fitch), in a neighboring stalk produces one that is round and solid? 

 Or, lastly, why should the suction of different species of Dipterous 

 larva? ( Cecidomyice), produce the wonderful galls found on our wil- 

 lows, causing in many instances not on]y a total change in the texture 

 of the leaf, but also in its mode of growth ? 



To me the formation of our Bark-louse scale appears somewhat-an- 

 alagous to all of these, and a thousand other such phenomena known 

 to science ; and in answering how such growths, peculiar to each spe- 

 cies, are formed, or why each is so constant in its character, I can only 

 say that it is their nature ; or, with Devere, " that knowledge of first 

 causes belongs to Him alone, who allows the eye of man to see final 

 causes only/' The more we endeavor to study the why and the 

 wherefore of these things the more the mind is filled with the idea of 

 Infinity, and escaping from all visible impressions of space and time 

 rises to sublimest contemplation of the Creator. 



The growth of the scale under consideration, to my mind, depends 

 no more on the will of the louse underneath it than does the sponge 

 on that of the slimy, jelly-like creature which secretes it, or the coral 

 on that of its polype; or, to use a more patent illustration, than the 

 growth of our bones, though secreted from our organs, depends on our 

 will. 



By carefully lifting one of these scales during the months of July 



