422 WILLIAM MORTON WHEELER 



larvae in spinning the silken web with which the leaves forming 

 the nest are held together. He also observed the bridges or 

 chains which these ants make of their own bodies in order to 

 draw^ the leaves together and to hold them in place, while other 

 detachments of workers are moving the spinning larvse back 

 and forth like shuttles across the gap. These bridges seem to 

 be very stable. One of them was carefully watched for a period 

 of 80 minutes, during which time none of the ants was relieved. 



Pierce ^"^ makes a few observations on the Texan harvesting 

 ants Pogonomyrmex harhatus var. molefaciens and Ischnoniyrmex 

 cockerelli. He claims to have found these two ants living to- 

 gether amicably, an observation open to considerable doubt. 

 On the nest crater of P. molefaciens he found seeds of 'a common 

 grass {Andropogon torreyaniis). This ant is most active during 

 the warmest part of the day, but remains in its nest when the 

 temperature rises to 114° F., with a ground temperature of 

 140" F. At such times the greatest activity is in the morning 

 or towards sunset. " It is also noticeable that the foragers are 

 not very far from the nests on cloudy days, and when a rain 

 seems imminent the ants are clustered within a few inches of 

 the entrance to the nests." 



Pieron ^"^ reviews in considerable detail the general subject 

 of social symbiosis in ants, devoting half of his article to an 

 account of the facts, the other half to a discussion of the various 

 hypotheses which have been advanced within recent years to 

 account for the phylogenetic development of temporary and 

 permanent social parasitism and slavery (dulosis). In the main 

 he accepts Wasmann's views, even where these involve erro- 

 neous interpretations (as in the case of the supposed dulosis of 

 the American Formica specularis), as opposed to the views of 

 Wheeler, Emery, Santschi. and Viehmeyer, and derives the pre- 

 datory from the parasitic types of colony formation. The 

 author's views, however, are vague and of little importance, 

 probably because he has made no observations of his own on 

 the subject he discusses. 



Santschi ""> calls attention to the fact that monandry, or 

 fecundation of the female by a single male, though assumed to 

 be the normal occurrence in the honey bee, owing to the tearing 

 away of the male genitalia during the nuptial flight and the 

 impossibility of further impregnation, has not been proved to 



