204 THE entomologist's record. 



Entomology at the Royal Society. 



The conversazione of the Royal Society was hold at Burlington 

 House, on the evening of May 19th. Entomologists mustered strongly. 

 Lord Walsingham, Prof. Poulton, Dr. Dixey, Messrs. Blandford, 

 Champion, Durrant, Ehves, Enock, Goss, Kirby, Lloyd, McLachlan, 

 Meldola, Merrifield, Salvin, Trimen, Tutt, Verrall, and Waterhouse, 

 were present. Mr. Blandford was in charge of a number of micro- 

 scopes, etc., illustrating The Tsetse Fly and the parasite of the 

 Tsetse Fly-disease, or Ngana. The Tsetse Fly disease, familiar 

 during the past fifty years as a scourge to domestic animals in Central 

 and South Africa, has been recently shown by Surgeon-Major Bruce 

 to be due to the presence in the blood and serous fluids of the 

 ali'ected animals of a parasitic Protozoon [Tnifianosoma). Surgeon- 

 Major Bruce has proved experimentally that the parasite may be 

 present in the blood of wild animals shot in the " Fly Country," 

 which, however, are not known to suffer from its presence. The 

 part played by the ily appears merely to be that of communicating 

 the micro-organism from infected to healthy animals. The disease of 

 animals known as " Surra," in Asia, is closely allied to Ngana, and 

 a similar parasite occurs in this country in the rat, but without 

 producing the same fatal effects. Dried specimens of the Hy, specimens of 

 the Ngana h^matozoon, both alive and stained, and of the rat ha^ma- 

 tozoon, were exhibited. Mr. Enock exhibited Microscopic Prepar- 

 ations OF the Mymarid.e, a small family of parasitic hymenoptera, 

 hitherto represented by some eleven genera, containing thirty-five 

 species. This number has been recently increased by eight new 

 genera, and many species. These most minute winged creatures 

 (the smallest one eighty-fifth of an inch long) lay their eggs within 

 those of other insects, which are thus destroyed by the tiny larvfe 

 feeding upon the contained fluid, which is sufficient to sustain the 

 parasite until it has reached maturity, when it bites a hole in the 

 shell and escapes. It will be remembered that Caraphractus cmctus 

 uses its wings for swimming under water. The exhibits of Dr. M. 

 Standfuss, of Zurich, were most interesting, and we congratulate the 

 talented exhibitor on the strength of mind that led him to trust 

 such valuable material to the tender mercies of carriers. The 

 Lepidoptera resulting from temperature experiments formed a most 

 instructive exhibit, and placed side by side, as they were, with some 

 of the more striking of Mr. Merrifield's specimens similarly obtained, 

 their value was much enhanced. The Hybrid Saturxiids, etc., were, 

 if anything, still more interesting. The exhibit comprised the products 

 of the crossing of various species, and the issue of these crossings by 

 re-crossing the hybrid males with the females of the original species, 

 or the pairing of these males with the females of a third species. A 

 number of most interesting Mongrels was also exhibited. These 

 were, of course, the products of crossing various local races (varieties 

 in the true sense of the word) of the same species. Mr, Merrifield's 

 interesting exhibit consisted of Insects which had been altered by 

 temperature applied in the pupal stages. The temperatures applied 

 were roughly three, rh. (1 ) Forced, about 80*^ F. to 104« F. (2) Cooled, 

 about 48" F. to 52o F. (8) Iced, about 84^ F. Summer pupa? are 

 generally much more affected than winter pupa? which, inmost species, 

 are not affected at all. The pattern appears generally to be most 



