54 THE ENTOMOLOGIST. 



produced by Aphilothrix Sieboldii, without perceiving their 

 very close correspondence with the small aborted acorns we 

 find so commonly on the long peduncles of Quercus pedun- 

 culatata. On these peduncles it is not unusual to find one 

 normally developed acorn near the base, and one, two, or 

 three aborted acorns beyond it, as though the first had 

 appropriated the sap destined for the nutriment of the others, 

 as well as its own. These aborted acorns are manifestly 

 represented by the galls in question, the stigma in both 

 instances being the only part of the acorn that protrudes 

 beyond the cup. — Edward Newman. 



The Synergi — or fellow-workers, or inquilines, or lodgers 

 — have been lately mentioned in the ' Entomologist,' and a 

 short abstract of Dr. Mayr's treatise on them may be of use 

 to the observers of galls. He praises Hartig's work as being 

 a good foundation for the history of oak-gall-making flies, 

 but observes that the above author is less successful with 

 regard to the Synergi, which failure, he says, may be owing 

 to the great difficulty in determining the often very variable 

 species. He adds that these difficulties can only be over- 

 come by continual researches, and by complete and plentiful 

 materials brought together and well arranged. He next says 

 that he has particularly studied the lodgers for a series of 

 years, and mentions his examination of Hartig's type speci- 

 mens, and the help he has received from correspondents, and 

 the division by Foerster of Hartig's genus Synergus into two 

 genera, Synergus and Sapholytus, and notices the characters 

 of these two genera, and also of Ceroptre, Phanacis, Peri- 

 clislus, and Xenophanes. The genus Ceroptre, he says, is 

 interesting on account of its biology. He has reared from 

 C. arator. Hart., more than six hundred females, but not one 

 male; and of C. Cerri, JSlayr, ninety-eight females, and only 

 four males, and he supposes that only so'me few females are 

 impregnated, but that the unfertilized also lay developing 

 eggs. He then defines two kinds of parthenogenesis : the 

 mixed parthenogenesis, of which C. Cerri is an example ; 

 and the Thelykotik, or simple female parthenogenesis, repre- 

 sented by C. Aralor. He next returns to the difficulty of 

 ascertaining the species of Synergus, owing to their great 

 variableness, of which S. melanopus, that lives in many 

 kinds of galls, is the chief example, and concludes that most 



