No. 614] THE USES OF INSECT GALLS 



157 



Another undetermined gall is that called by Pomet 

 "Bazdyendge" and described by him as a reddish gall 

 on a species of oak in Turkey, which was used with cochi- 

 neal and tartar to make a very fine scarlet. 



So far as can be ascertained no American galls were 

 ever used for any practical purpose by the Indian (state- 

 ment of Dr. Hough, U. S. National Museum), and but 

 few by the white man. No interest appears to have been 

 taken in this phase of gall history in America until 

 Trimble, through his interest in the history of tannins, 

 took up the question of tannic acid in galls and analyzed 

 a few North American galls. He found that many of 

 these galls contained relatively large amounts of tannin. 

 He stated that there are more oaks in the United States 

 than in Europe which are available for tanning, and that 

 as the gall partakes of the character of its host-plant then 

 there must necessarily be more oak galls in this country 

 suitable for tanning. He also remarks that it is not 

 known that all species of oak yield the same tannin, there- 

 fore we may look for a variation in the properties and 

 composition of the tannins from different species. 



Of the Cynipid galls examined by Trimble the richest 

 in tannin is one from Texas, on Qu&rcus virens, closely 

 resembling the Aleppo gall and containing 40 per cent, 

 tannic acid. This has been identified by Mr. S. A. Rohwer 

 as Disholcaspis cinerosa, Acraspis erinacei (determined 

 by L. 0. Howard) was found to contain 17.89 per cent, 

 tannic acid and Disholcaspis globulus Fitch, 3.91 per cent. 



. A Dipterous gall on Quercus alba, determined by L. 0. 

 Howard as Cecidomyia or Diplosis species, contains, ac- 

 cording to Trimble, 9.24 per cent, tannic when air-dried, 

 and 31.68 per cent, when quickly dried by artificial heat 

 at 80 degrees. 



A gall occurring on Rhus glabra, in many ways the 

 counterpart of the Chinese gall, was found by Trimble 

 to yield, when air-dried, 61.70 per cent, tannic acid which 

 is about 8.3 per cent, less than the Chinese galls yield and 

 about 3 per cent, less than the Aleppo. This has been 



