318 PROCEEDINGS OF THE ACADEMY OF [Apr., 



odors these ants carried pores on only 62 per cent, of the bases of 

 their wings. Might not the difference of 0.40 second in reaction 

 time between the reaction time of these wingless ants and that of 

 the winged sisters be due to the fact that the pores on 38 per cent, 

 of the wings were prevented from functioning? 



To ascertain if a greater percentage of wings including the pores 

 could be pulled off artificially, the wings of 37 more winged females 

 Were pulled off. This time greater care in pulling off the wings was 

 taken. These wings were also examined microscopically. Counting 

 all the wings from both lots of ants, 62 ants in all, 50 per cent, of the 

 wings pulled off bore pores. Of the front wings pulled off 52 bore 

 pores and 72 were devoid of pores. Of the hind wings pulled ofT 

 72 bore pores and 52 were devoid of pores. 



To ascertain the percentage of wings including the pores actually 

 lost by the natural method, many detached wings from the virgin 

 females were removed from the large glass cage. These wings were 

 certainly shed in the same manner in which the wings of female ants 

 are shed in nature. The worker ants had carried great numbers of 

 these detached wings out of the nest and had laid them on the 

 refuse pile. Of the 786 detached wings of females examined micro- 

 scopically only 18 per cent, of them bore pores. Of the front wings 

 120 bore pores and 365 did not bear pores. Of the hind wings 21 

 bore pores and 280 did not carry pores. Thus one-third of the front 

 wings bore pores, while only one-thirteenth of the hind wings bore 

 them. As stated on page 311, the average number of pores for both 

 front wings of one of these females is 320, and the average number 

 of pores for both hind wings of the same female is 98. With these 

 females it is, therefore, evident that when the wings are shed only 

 21 per cent, of the pores as an average are lost, while 79 per cent, 

 are not prevented from functioning, because the wings devoid of 

 pores always break off at a weak place (text fig. 1 and Plate XI, fig. 

 25, XX, yy) in the chitin just distal to the groups of- pores. The 

 wound made by the wing breaking off at this place cannot affect the 

 sense cells in the least because a thick layer of chitin separates these 

 cells from the outside air. 



One of the virgin females which had recently shed her wings was 

 examined. All four of the bases of the wings of this female were 

 left intact. 



3. Wings of males of Formica pulled off. 



The wings of 7 males of Formica were pulled off and the mutilated 

 males were tested with odors as usual. They appeared normal in 



