446 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
supposed clouds reached Freetown and proved to be a continuous mass 
of locusts, which passed without intermission till 5 . 10 p.m. Myriads 
settled but made no apparent difference in the size of the swarms. The 
whole town was covered with their excrement. At 9.45 a.m. the next 
day the stream began again, but not in such dense masses, and continued 
up to 1 p.m. The species has been found to be Pachytylus migratoroides, 
originally described from Abyssinia. 
Dipterous Parasites of Locusts.* — M. J. Kiinckel d’Herculais notes 
a number of cases now known in which Bombylidae are parasitic in the 
eggs of Acridiidee, and not as usual in the larvae of Hymenoptera. He 
has himself studied the Bom bylid larvae found in the ova of Stauronotus 
maroccanus, The larva- emerges from the egg in August, reaches the 
limit of its growth in October, passes the winter in “ hypnodie ” within 
the egg-case, and is hatched the following summer. The hypnodie state 
may be prolonged for as many as three winters. The metamorphosis is 
divided into two stages ; in the first the nymph is active, in the second 
very inactive ; the usually continuous phenomena of histolysis, asso- 
ciated with metamorphosis, are here interrupted by an interval of several 
days. 
He f finds that Stauronotus maroccanus , Acridium segyptium , and other 
Acridiidse are followed on their devastating march by various viviparous 
Diptera, e. g. Sarcophaga atropos , Meigen, S. cruentata Meigen, S. nurus 
Rondani, which deposit their larvae in the bodies of the locusts. The 
parasitism of these larvae results in a sort of rachitic condition ; the fatty 
body is devoured, the wing-muscles are enfeebled, the gonads atrophy. In 
short, parasitic castration and “ aptenia ” result, for which the Diptera 
deserve acknowledgment. 
Tracheal System of Locusta.f — Dr. Y. Nietsch notes the rarity of 
precise figures or descriptions of the tracheal system of insects. He 
figures and describes that of Locusta viridissima. There are ten stigmata. 
The 1st leads to five branches, two dorsal, two ventral, and a very strong 
one to the tibia of the first leg, where the auditory organ lies ; the 2nd 
has two branches, to second leg and anterior wing ; the 3rd has four 
branches, a ventral, two dorsals, and one to the third leg ; the 4th has 
five, two ventral, two dorsals, and a visceral ; the 6th and 6th have four, 
a ventral, two dorsals, and a visceral ; the 8th-9th have five branches, a 
ventral, two dorsals, a branch to the intestine, and one to the repro- 
ductive organs; the 10th has three branches, two dorsally, and a ventral 
which gives off three viscerals. 
Tertiary Tipulid8e.§ — Mr. S. H. Scudder has published an important 
monograph on the remains of these insects ; several hundred specimens 
collected in the famous Florissant deposits have “ not only the venation 
of the wings completely represented, with all their most delicate mark- 
ings, but also the slender and fragile legs with their clothing of hair and 
spurs, and to some degree at least the antennae and palpi. Even the 
facets of the compound eyes are often preserved as in life.” With such 
* Comptes Rendus, cxviii. (1894) pp. 926-9. f Tom. eft., pp. 1106-8. 
t Ver. Zool.-Bot. Ges. Wien, xliv. (1894) pp. 1-8 (1 pi.). 
§ Proc. Amer. Phil. Soc., xxxii.; see Amer. Natural., xxviii. (1894) pp. 532 and 3. 
