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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 11 
ment were carried out, making a total of 63 experiments. Of these,, 
aside from the one already recorded, three were partial successes, the 
remainder were failures. Twenty-six queens died or were killed by 
the workers a few days after they were fertilized and before sufficient 
time elapsed to allow of egg production. The remainder laid eggs in 
sufficiently large quantity to ascertain the sex of the progeny or else 
the queens were killed and opened, after a few drone eggs had been laid, 
and the spermatheca found to contain no spermatozoa. 
The method followed in the operation was as follows: Being unable 
to secure successful manipulation by squeezing out the drone organs 
and allowing the spermatic fluid to drop into the posterior chamber of 
the female, we carefully dissected out the seminal vesicles of mature 
drones, using sterile instruments to mix the contents with a drop of 
sterile salt solution (0.75 gr. to 100 cc. H 2 0). In the later trials the salt 
solution was not used, its purpose being merely to dilute the spermatic 
fluid for greater facility in handling. During cool weather the instru¬ 
ments were kept warm. If the spermatozoa were inactive the material 
was discarded and a new preparation made. The queen was held 
loosely between the fingers of the left hand, the posterior end upward. 
With the right hand a capillary tube into which the spermatic fluid had 
been drawn was then inserted into the bursa copulatrix of the queen 
and the contents gently forced into the vagina by pressure from the 
mouth. The queen was then placed in a queenless colony and left 
under normal conditions, except that a queen excluder was applied to 
the hive next to the bottomboard. 
To prevent the possibility of natural fertilization each queen was 
taken as soon as she emerged from the queen cell and one or both pairs 
of wings clipped off. All drones were removed from the hives and a 
queen excluder kept on. Queens were taken at all ages, varying from 
two to thirty-five days, although the majority were treated at the age of 
six to seven days. During 1916 practically all the queens were fertil¬ 
ized at the time when they were trying to leave the hive, apparently for 
the marriage flight. 
Only mature drones were used. Careful observations showed us 
that drones were mature and spermatozoa active when they were five 
to six days old, but most of those used were ten days or more of age 
and had had several flights. 
Where queens laid eggs from eleven to forty days intervened between 
the attempted fertilization and egg laying, with an average of twenty 
days. During 1916 whenever a queen attempted to escape from the 
hive for a flight she was refertilized. In this way some were operated 
upon two to three times, but still with no results. 
The three partial successes were as follows: One thirteen-day-old 
