August 20, 1915] 



SCIENCE 



253 



Since the closing of the Mount Weather re- 

 search observatory last winter, the Blue Hill 

 Meteorological Observatory is alone in the 

 United States in regularly flying kites in the 

 international days. However, the Weather 

 Bureau is planning to resume aerological 

 work at Omaha. 



A MAP of the eastern United States showing 

 the frequency of dry spells during the last 

 twenty years in the months of April to Sep- 

 tember inclusive was published in the National 

 Weather and Crop Bulletin, May 4, 1915. The 

 greatest frequency is found in the Great 

 Plains district and the least in the southern 

 Appalachians. 



Dr. W. Koppen, after study of the monthly 

 period in the weather^ has come to the conclu- 

 sion that the moon has no noticeable influence 

 on meteorological phenomena. 



A KNIGHTHOOD has been conferred on Dr. W. 

 N. Shaw, director of the British Meteorolog- 

 ical Service. 



Mr. Aksel S. Steen, who recently suc- 

 ceeded Dr. Mohn as Director of the Norweg- 

 ian Meteorological Institution, died in Chris- 

 tiania on May 10. 



A NEW departure in the distribution of 

 weather forecasts is announced from Illinois 

 where a newspaper man and the Springfield 

 Watch Co. send out the predictions by wireless 

 telegraph. 



Charles F. Brooks 



Washington, D. C. 



SPECIAL ARTICLES 



ON THE REPRODUCTIVE AND HOST HABITS OF 

 CUTEREBRA AND DERMATOBIA 



In view of the considerable mystery sur- 

 rounding the host habits of Dermatohia hom- 

 inis, the man-infesting hot of tropical America, 

 now believed to employ bloodsucking mosqui- 

 toes of the genus Janthinosoma for the car- 

 riage of its eggs to the host, the following 

 recently discovered facts relating to the repro- 



5 Concluded in Meteorologische Zeitschrift, April, 

 1915. Translated in Monthly Weather Bureau, 

 April, 1915, pp. 179-181. 



ductive habit of Cuterehra will be of interest, 

 since Dermatohia belongs to the same restricted 

 group of flies. 



On June 25, 1915, Mr. Eaymond C. Shannon, 

 of the Bureau of Entomology, found a female 

 Cuterehra cuniculi on the stem of a plant in a 

 low moist spot near a stream in the vicinity of 

 Beltsville, Maryland. The fly was inactive, 

 and had probably recently emerged from the 

 puparium. It was kept alive until July 2, 

 1915, when it was seen to be growing weak, 

 whereupon it was killed and dissected. 



The uterus was found to be of the double-sac 

 incubating type, much after the style of Sarco- 

 phaga, probably independently developed in the 

 Cuterebidas and not indicating any close rela- 

 tionship with the Sarcophagidse. The uterus 

 was estimated to contain well over five thou- 

 sand eggs and perhaps nearer ten thousand. It 

 is difficult to make a close estimate, as the 

 eggs are disposed in bunches at various angles 

 to each other and the two large sacs which con- 

 stitute the uterus are irregularly rounded. 



The egg is elongate, about 1.Y5 mm. in 

 length, about .4 mm. in greatest width, gently 

 tapering toward tlie caudal end, suddenly 

 tapering at the cephalic end, with tough extra- 

 thick and strong reticulated chorion of a deep 

 salmon color, and is furnished with an oper- 

 culum or lid on one side at the cephalic end. 

 The lid hinges by its cephalic edge, but is 

 easily completely detached. The chorion ap- 

 peared to be particularly viscid at and near 

 the caudal end. The embryo was undeveloped. 

 The tubular glands are large and evidently 

 functional, and contained a deep rufous-yellow 

 substance. The ovipositor is simple and with- 

 out any piercing structure. 



The presence of the incubating uterus, en- 

 veloped with tracheae, indicates that the egg 

 is held within the fly until the maggot is well 

 formed. The presence of the thick chorion 

 indicates that the maggot is ejected still en- 

 sconced within the shell, or that practical 

 oviposition takes place. The simple structure 

 of the ovipositor shows that the egg is not 

 thrust through any integument or surface. 

 Moreover, the fact that the chorion is tough, 

 extra-strong and deeply colored indicates that 



