VII PARTHENOGENESIS 257 



successfully through all the stages above noted. 

 Firstly, they furnished a virgin colony in a nest ab- 

 solutely free from eggs and larvae except a few 

 advanced larvae purposely left in some nests and noted 

 down which colony laid eggs ; secondly, these eggs 

 produced without exception (some few eggs not 

 developing) males. 



The method of recording which was used must be 

 mentioned to give a notion of the accuracy of the 

 observations. A series of plans of each nest was kept, 

 each cell being represented and its contents at differ- 

 ent dates. Successive plans were used for recording 

 the successive changes in the number of cells of the 

 nest, and in their contents at different periods of the 

 observations. Signs jotted down in the plan cells 

 indicate such facts as these e.g. the cell contains a 

 "parthenogenetic egg," or "a second parthenogenetic 

 egg which was laid after a first one had disappeared," 

 or " a larva sprung from the queen," or " a partheno- 

 genetic male larva/' etc. etc. A second record was 

 kept, and is given for twenty-two cases, in which the 

 following facts were noted : Number of the nest, 

 date it was made movable, number of cells at that 

 time, day of emergence of first worker-female, date of 

 destruction of queen, eggs, and grubs, number of larvae 

 and pupae left undestroyed at this date, date of first 

 laying of parthenogenetic eggs, date of first emer- 

 gence of parthenogenetic larvae, date of first emergence 

 of drones born from queens' eggs (these were null in 

 most cases, and were always so late as not to affect 

 the experiments by possibly impregnating the worker- 



