48 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



I saw them crowding closer together until a narrow curve was 

 distinguished at the head of the larva, and other curved Hnes 

 were formed by the red cells forming up into close order, which 

 increased in intensity as more cells appeared to be attracted and 

 drawn together, until in from four to five weeks there was a distinct 

 form of the imago marked out by the massed cells, which week 

 after week became more distinct (Fig. 14), and I could clearly see the 

 shape of the head, thorax, and abdomen. Then the limbs were mapped 

 out in the same wonderful manner, and just the dehcate outline of 

 the legs, ovipositor, antennas, and wings. On turning to the head, I 

 noticed some minute crimson specks at exact distances from each 

 other, which after much thought I realized as the facets of the 

 compound eyes ! In two months from the time v/hen the larva became 

 full-grown, I had seen taking place under the microscope the forma- 

 tion, by the gathering together of the cells, of all the various organs of 

 the embryo, which in another week or two appeared to have absorbed 

 all the cells, which commenced to lose their red colour and become 

 brown chiton, the various parts being more or less covered with 

 hairs. After another week I could see the tiny jaws at work, en- 

 deavouring to nibble a hole through the old eggsheU. (Fig. 15.) Some 

 hours v/ere occupied in this work before the tiny parasite was able 

 to wriggle through the pith to the opposite side, where its further 

 progress v/as barred by the thick green covering of the rush ; but, 

 nothing daunted, it went on dihgently nibbhng until it had made a 

 hole large enough for its passage (Figs. 16, 17) and emerged for the first 

 time into light and air. A short rest on the rush, to brush its 

 body and limbs with the wonderful brushes and combs which are 

 so artfully concealed on each limb, some used for brushing out the 

 long cilia round the margins of the wings, and those on the front tibia, 

 of semicircular form, specially contrived to fit the antennae, which were 

 brushed one at a time most carefully. A final shake of the exquisite 

 wings and away flew the Fairy Fly on its virgin flight (Fig. 18), soon 

 to find a partner, and then to search for the eggs of Liburnia, and 

 another brood is started. In some genera (especially in that of 

 Anagrus) the males are fairly common, but when scarce (and among 

 some, the males are still unknown) the females are parthenogenetic, 

 or, as in some instances, the males are apterous, and do not leave 

 the host egg, copulation taking place before the females emerge 

 from the host egg. I have frequently observed this in an alHed species, 

 Pvesiwidiia aquatica (Lubbock), which oviposits in the eggs of the Large 

 Water Beetle. Several times I have bred from thirty to forty from 

 a single egg ! 



As might be expected from this Httle-known family of ovivorous 

 parasites, many wonderful facts in their habits and economy are 

 brought to light by constant research, and even then we feel how 

 little we know about most of the genera, in many instances the only 

 known facts being their date of capture and locahty. Take, for instance, 

 the genus Gonaiocerus. Many times we have swept up twenty to 



