VOL. XVII. LONDON, ONT., FEBRUARY, 1885. No. 2 



THE COLLECTION OF PHYTOPTOCECIDIA, OR MITE 

 GALLS, IN THE CAMBRIDGE MUSEUM. 



BY DR. H. A. HAGEN, CAMBRIDGE, MASS. 



The very extensive collection of galls from the U. S. presented to the 

 Museum in 1870 by Baron von Osten Sacken, contains all his types. There 

 are 138 different galls of Cynipidae, gall flies 56 species, guest flies 23 

 species, parasites 66 species, and from Dr. Reinhard 38 types of European 

 Cynipid^. Further galls of other insects 121 species (Diptera 70, Hem- 

 iptera 30, etc.) ; the types of B. D. Walsh, galls of Salix, 13 species. To 

 these were later added by the Baron his types of Colorado galls, 12 

 species, and those of California, 15 species. The permanent aim to 

 enlarge this excellent collection has met with success. The prominent 

 additions from Europe are 88 species from Mr. Brischke, in Danzig, 

 Prussia, and 96 types of oak galls from Prof G. Mayr, in Vienna, Aus- 

 tria, and 18 types of mite galls from Dr. Thomas. The additions of N. 

 Am. galls are very numerous ; prominent among them are large additions 

 from California, Washington Terr., and Mexico. 



There were among the galls of the Baron a small number of mite 

 galls ; fortunately, also, the types of the two species described by Mr. 

 Walsh, and a number of fungi. As some deformations of plants 

 by insects are very similar to the deformations by fungi, it was decided 

 best to make also a collection of fungi. For the determination of these 

 and of the mite galls, formerly considered to be fungi, I am deeply in- 

 debted to the untiring kindness of Prof W. J. Farlow, who has also added 

 to the collection a large number of specimens. 



The advancement of the scientific knowledge of the mite galls is com- 

 paratively new and principally due to the numerous and incessant studies 

 and publications of Dr. Fr. Thomas, in Ohrdruf, Gotha. His yearly 

 Reports in Dr. L. Just's " Botanischer Jahresbericht " are indispensable to 

 the student of mite galls. 



The literature of the mite galls of the U. S,, as far as known to me, is 



