xxiv 



Chapman on M. purpurella. Observations were afterwards made Oil 

 M. unimaculella, Incurvaria muscalella, Adela, Nemophora, Lampronia, 

 Nematois, Pancalia, Tinagma, Gtyphipteryx and certain Coleophorce. 

 With regard to the apparatus with which the females of semipurpurella 

 are provided, Dr. Wood states that it " lies within the abdomen, is 

 placed above the viscera and works free in the general body cavity. 

 It consists of two pairs of strong, black, chitinous rods, reaching from 

 the anal extremity, two or more segments upwards. To the proximal 

 end of each rod are attached powerful muscular bands, which pass 

 backwards and are inserted in or near the underside of the last 

 dorsal plate. The distal ends of the lower pair of rods are united to 

 the last ventral plate, and their use is to open the anal orifice, afford 

 an anchorage in the surface of the leaf at the commencement of the 

 operation of cutting the pocket, and later on to advance the point of 

 the ventral plate within the orifice of the pocket and keep it on the 

 stretch. The upper pair of rods are united to the corners of a very 

 beautiful and complicated instrument, which we may call the knife 

 blade. Its extremity has very much the shape of a surgeon's 

 lancet, but instead of the cutting edge, it is armed on each side with a 

 fine saw. Its use, and, up to a certain point its mode of action by 

 the alternate working of the rods, are so self evident that it 

 is unnecessary to dwell upon them. The knife is provided 

 with a sheath, and both are concealed within the abdomen 

 when not in use." Drs. Wood and Chapman then found that the 

 females in Glyphipleryx and certain species of Coleophorce were 

 provided with an ovipositor, " very similar in outward appearance to 

 the fore-going, and like them rigid, yet highly elastic, and capable of 

 being freely protruded. In form it was flat, broad, thin and pointed, 

 but in spite of its lancet-like shape, it was incapable of cutting, and 

 had evidently been designed to enable the insect to place its egg within 

 an unopened floret." Since then Lampronia, Adela and Nemophora, 

 have been added to the list of those with the leaf -cutting apparatus, 

 and probably Nematois, Pancalia and Tinagma. In Adela and Nemophora, 

 the end of the knife is conical or trowel-shaped, and is used to scoop 

 out a hole in a stem &c., in which to place the egg. In Lampronia, the 

 knife is chisel-like, and the egg is laid in the receptacle of the flower. 

 The way in which the whole complex arrangement connected with 

 oviposition has been worked out in these insects, reflects the greatest 

 credit on the industry and observation of the two gentlemen who have 

 done it. 



There are many other minor " secondary sexual characters " that 

 have been purposely left out, and several facts relating to the headings 

 discussed which might have been inserted. In a paper of this kind 

 the difficulty is to keep so wide a subject within bounds, and this is 

 why so many matters, highly interesting in themselves, but not bearing 

 particularly on variation, have been neglected. 



