58 ' ' [March, 



whole set eoml)ine into a single dagger-like weapon, something like a 

 Malayan kris ; a structure like this would by itself be strong evidence 

 that, notwithstanding the carnivorous habits of the advilt, the eggs are 

 laid in the tissues of plants. Aniyot and Serville refer to what purports, 

 under the name of Gimex suhaj^ferus, to be a description from De Geer's 

 " Memoires pour servir, etc." of the eggs of this species. This descrip- 

 tion, however, does not apply to our present subject, but to what is now 

 known as Coranus suhcvpterus, an entirely different insect. Dr. T. A. 

 Chapman seems to have been the first to discover the eggs, and he found 

 them imbedded in the stems of Ghlora perfoliata (Entomologist, 190G, 

 p. 73). Some fourteen years ago he saw growing on the Downs ir 

 Surrey, stems of Chlora which showed, at the beginning of July, a 

 number of slightly raised circular marks, about 0-21 to 0'24 mm. in 

 diameter. They were placed in a straight line down one side of the 

 stem, usually in its second or third internode, and about 2 mm. apart. 

 They were found to be the ends of eggs which passed at right angles 

 through the haixl outer layers of the stem and then bent down through 

 the central pith so that the main part of the egg was parallel to the 

 length of the stem. The time of oviposition is not known, but it w^ould 

 apparently be in spring-time, when the C/ilora-i-.ten\s would be com- 

 paratively soft. But, be that as it may, it is not easy to understand 

 bow an ovipositor with a wavy blade such as described above can be 

 ■used so as to produce such a perfectly circular and smooth hole. 

 Hungerford (Univ. Kansas Sc. Bull. Dec. 1919) has described a similar 

 arrangement of the eggs of Mesovelia mulsanti White in the stems of 

 water plants, and states that the $ , rocking the body slightly from side 

 to side, causes the entire drill (which in this case is spear-shaped) "to 

 rotate or twist back and forth on its axis, rapidly at times, or again 

 .ni)re slowly as may suit the necessity of the work, until a hole is 

 effected and the ovipositor is buried to its base." If such a method is 

 applicable in our present case, the movement must be more complicated 

 because of the difference in the shape of the borer. The egg apparently 

 becomes enlarged after deposition, as the opening in the stem exactly 

 ■fits it at its smallest diameter, and the part imbedded is much broader. 

 The egg has a smooth, tough sl'in, and is of a pale yellowish colour. 

 It is closed by a kind of stopper which is pushed out wlien hatching 

 takes place, though it still remains attached to the ejg by several 

 twisted fibres and in a position as if its being pushed back into its place 

 were contemplated. 



In August 1918 I found on the Chiltern Hills in S. E. Oxfordshire 

 a somewhat different arrangement of eggs, which, nevertheless, I think 



