148 Journal New York Entomological Society. tVoi. xxiii. 



the warm rocks. Professor Zeller took this species on the high 

 Mensa and on Spitzberg in the Riesengebirge ; I have taken many- 

 specimens of it on our Schneeberg and the nearer but smaller Bisam- 

 berg, but among these were only three females. . . . On the occur- 

 rence of a storm the flies like other insects desert the peaks and hide 

 in crevices or other protected places. But they are not afraid of 

 a strong wind, and with astonishing endurance endeavor to maintain 

 themselves at the top. The preference of these flies for rocky peaks, 

 old towers and isolated triangulation pyramids is very useful to the 

 entomologist, who can obtain them there, although elsewhere they 

 would be extremely rare. We are indebted for the discovery of this 

 habit to the entomologist Saxesen in the Harz. . . . 



" The deposition of the larvce I was once enabled to observe very 

 closely in Ccphcnomyia rufibarbis. It was on a hot day in May, 

 after a morning shower, and the air was still and sultry. In the 

 warm sunshine these Qistrids were flying and encircled in vertical 

 arcs the heads of the deer [stag, Hirsch]. While the fly circled noise- 

 lessly, the deer followed it with its eye, stamped angrily, and often 

 closed the nostrils and breathed heavily. Suddenly the fly darted at 

 the open nostril, not alighting, but instantly turning back; this was 

 repeated several times. The deer began to sneeze, struck out with 

 its fore feet, attempted to scratch its nose with its hjnd foot and to 

 rub it on its fore leg; at length it started to run, stopping in a short 

 distance to sneeze, strike, scratch and rub as before. The fly was 

 several times driven to the ground by the sneezing of the deer, but 

 recovered itself with a loud buzz and flew slowly away. 



" Even a single fly of this kind produces a marked effect upon 

 a herd of deer; immediately the deer all prick up their ears, look 

 up in the air and close their nostrils. While the Cephenomyia female 

 flies among the herd, depositing her maggots one by one, a peculiar 

 rhythmic movement passes over the animals, snorting and stamping 

 followed by quiet, and this repeated three or four times, until the 

 fly departs or the herd scatter into deep woods, when the same play 

 is repeated with a nearby herd. 



" The strong responsive movements of the host are explained by 

 the fact that the fly deposits, each time she approaches the nasal 

 opening, a drop of fluid with very active living larvae; these attach 

 themselves at once with their strong booklets and thus induce the 



