THE 



CIjc l^mcricaii ^ntamoloigist. 



PUBLISHED MONTHLY BY 

 R. F. STXJI3LE-ir Sc CO., 



104 OLIVE STREET, ST. LOTJIS. 



EDITORS : 



HEXJ. D. WALSH Rock Islam!, III. 



CH.VS. V. IllLEY, 2130 Clark Avi- St. Louis, Mo. 



tULLS AND THEIR .\RCHITECTS. 



In llic liuiguaiie ol X;itiirallsti=, '-galls"' lire 

 all such (lelonnutioii.s of living and growing 

 phiiits. as arc produced by one or more insects 

 or other allied animals residing therein, and 

 deriving their nourishment therefrom. For ex- 

 ample, the common ■•nut-galls'' of commerce, 

 to be found in every druggist's store, and which 

 are such an indispensable ingi-edient in all our 

 writing-inks, are caused by an exotic species of 

 Gall-fly (Ci/nips) attacking an exotic species of 

 oak, as our common oak-applos (Fig. 78) arc 

 caused by an American (Jail-fly, very .similar 

 to that shown in figure si, but smaller, attack- 

 ing an American oak. In the language of 

 surgeons and butchers, the word "gaH" has a 

 very dift'erent meaning, being applied to the 

 fluid otherwise known as bile which is contained 

 in the gall-bladder. But with this use of the 

 term we have now nothing to do. 



Galls are of various sizes and colors, and of 

 almost every conceivable shape. Some resemble 

 a large rose, some have the appearance of a 

 pine-cone (Fig. 82). some imitate the sprouts 

 from a cabbage-stalk (Fig. 8i), some look like a 

 tomato (Fig. 8!)). some like a potato, some like 

 an apple (Figs. 78 and Fig. 85 «), some like 

 smallerfruits (Figs. 7'J, and Fig. 80 «)> some like 

 the garden flower known as Cockscomb (Fig. 

 87), and some like the veritable comb of a 

 cock (Fig. iio) . Some again are smooth, some 

 wrinkled, some downy or hairy, a few so trans- 

 ])areut that the living insect can be seen inside 

 them, hut most of them impervious to light. 

 Some on the other hand are so fragile that they 



<au be readily crushed in a child's fingers, some 

 so hard and woody that itreciuires a sharp knife 

 to cut into them. Finally in color they are of 

 various shades of green, yellow, crimson and 

 brown, often prettily speckled and mottled, and 

 in many cases they have as rosy a cheek as a 

 peach. 



•'As bitter as gall"' is a very common ex- 

 pression, but galls are by no means generally 

 bitter. The nut-galls, indeed, of commerce arc 

 well-known to be so, and the Oak-plum Gall 

 (Fig. 80, n), when green, seems to contain the 

 very concentrated essence of quinine. But the 

 great majority of these vegetable excrescences 

 scarcely ditt'er in flavor from the plant upon 

 which they grow. This is the case, for example, 

 with some fifty dift'erent kinds of galls that grow 

 upon difl'erent species of oak. And yet the 

 very same species of oak which when punctured 

 by "the Oak-plum Gall-fly (Fig. 81) produces 

 from the cup of the acorn this inten.sely bitter 

 gall, when i)unctured by a very similar fly be- 

 longing to the same genus (Cyiilps q. .scu/pla. 

 Bassett) generates from the leaf a gall which 

 looks for all the world like a grape, and which 

 is as fleshy and juicy and as pleasantly acid 

 as a partially ripe grape. Strange that two such 

 closely allied insects should cause upon the 

 very same plant such very dift'erent products I 



Almost every part of a plant is specially at- 

 tacked by gall-makers. Some confine them- 

 selves to the flower, some to the woody parts 

 such as the twigs and larger branches, some to 

 the roots, and a great number to the leaves. 

 As a general rule, each gall-maker confines it- 

 self to its special part of the infested plant ; but 

 we have noticed several remarkable specimens 

 where a certain gall-maker which habitually 

 attacks the twig, forming thereon a closely- 

 compacted series of galls, each of them about 

 the size of a pea (the oak-fig gall of Fitch). 

 •• slopped over," so to speak, when it arrived at 

 the terminal bud of the twig, so as to cause 

 several galls to develop next year, not from the 

 twig itself, but from one of the leaves at the 

 tip of the twig. And yet, strange to say. these 

 abnormal galls, generated by mistake upon a 

 pari of the plant where tlioy had no business to 



