ADELE M. FIELDE. 



on August 31. Only five cocoons were formed in this nest, and 

 each of these rendered a large, fine male. 



DR. FIELD'S GROUP C. Formica argcntata. 

 Dr. Irving A. Field, who simultaneously with myself, seques- 

 tered pupae from the same wild west that provided my B 

 group, likewise segregated virgin workers, to the number of one 

 hundred and twenty-five, all hatched between August 20 and 

 September 23, 1904. From eggs laid between June 6 and 13, 

 1905, the first larva appeared on June 21 ; the first cocoon on 

 July 23 ; and the first callow on August 7. All the young pro- 

 duced in this group were males, of which fourteen had appeared 

 before September 3, 1905. 



DR. FIELD'S GROUP D. Formica pallidc-fnlva fuscata. 



This group, while failing to meet prescribed conditions in so far 

 as the workers were not sequestered during the whole of their 

 lives, is herein inserted because its history is clearly recorded. 

 It con-ibted of many workers, secured by Dr. Field, at Middle- 

 sex Fells, Mass., on March 15, 1904. The ants were frozen in 

 a mass when taken from the ground, and every ant was so care- 

 fully examined before her insertion into the artificial nest that 

 there is no probability that eggs were introduced into the segre- 

 gated group of workers. This group remained under Dr. Field's 

 observation at Harvard University. It was placed in a chamber 

 having a temperature of from 75 to 85 F. or from 23 to 30 

 C. On March 20, five days after the sequestration, the first egg 

 was laid ; on April 4, the first larva appeared ; and on April 17, 

 the first cocoon was spun. Before June 10, forty-six males had 

 appeared in this nest ; and no other than male young had been 



produced. 



GROUP E. Crcuiastogastcr lineolata. 



The progeny of a queen ant whose life-experiences have all 

 been under observation, is believed to be here for the first time 

 enumerated. 



On August i 8, 1903, a queen Crcuiastogastcr lineolata hatched 

 in a sequestered group of pupae in one of my artificial nests * 



1 My ants were under my care at the Marine Biological Laboratory at Woods 

 Holl, Mass., during the summers, and at my home in New York City during the re- 

 mainder of the year. 



