262 ENTOMOLOGICAL SOCIETY 



is, however, a third explanation, which, if verified by future in 

 vestigation, would prove to be another interesting discovery in 

 connection with these oak gall-flies, viz., that the same species 

 may indifferently produce a gall on the root or on the twig. 

 When we remember how closely these two parts of the plant 

 are related physiologically and how readily the one in most trees 

 may be converted into the other, such a discovery should not sur 

 prise us. 



From the facts given in this case, although the act of oviposi- 

 tion was not carefully followed, it is yet obvious that the eggs 

 could not have been inserted in the manner described by Adler. 

 The facts as already suggested comport more with the conclu 

 sions of Hartig, though they indicate quite a different method of 

 oviposition than that described by either, in that the fluid egg-con 

 tents are not passed from one pole to another rapidly during the 

 act of oviposition as described by Hartig, but very gradually, the 

 process not being completed till just before the hatching. 



Again, a small, black, wingless species {Biorhiza nigra 

 Fitch, subsequently described as B. politus by Bassett) is not 

 infrequently found, during late winter, under the shelter of bark 

 scales, and oviposits, during late winter, in the terminal buds of 

 Quercus alba and Q. obtusiloba. The ovipositor in this case, 

 as in most cases where eggs are laid in dormant buds, is thrust 

 down between the bud-scales until it reaches the soft latent cell 

 tissue toward the centre of the bud. And here it is easy to ob 

 serve, by removing the scaly coverings, that the pedicel or stalk 

 only, which is about ten times as long as the egg-body, is in 

 serted in the leaf tissue, and the enlarged portion or egg-body is 

 at first external, being pressed and somewhat flattened by the sur 

 rounding leaf -scales.* 



In still a third case, of a small black inquiline ( Ceroptus po 

 litus Ashm.), oviposition was observed by Mr. Pergande in the 

 midrib of Quercus rubra, May 20, 1884, and in this case, as 

 my notes show, the egg is thrust down into the puncture made 

 by the terebra in the midrib until not a vestige of the egg is visi 

 ble, the pedicel being very short. 



There is, therefore, good reason for believing that oviposition 

 in these insects follows no uniform system, and there is a serious 

 question whether Adler's rejection of Hartig's views is justified. 



* This fly produces, according to experiments made for me by Mr. J. G. 

 Barlow of Cadet, Mo., an undescribed vesicular bud-gall, from which issues 

 a small black-winged bisexual s,^QC\Q&^Dryophantavestculotdes MS. mihi). 

 The gall produced by this and from which the apterous agamic genera 

 tion comes is not yet known, though it will probably be a leaf-gall similar 

 to that of Acraspi$ erinacece Walsh. 



