Whiting: Heredity in the Honey-Bee 



nuclei could unite in an egg without an 

 egg nucleus, then a female might result 

 possessing all the racial characteristics 

 of the father, but in every way a normal 

 female. 



The determination of sex then is not 

 due to the source of the germinal mater- 

 ial but rather to its quantity. In other 

 words each caste,^ — drone, queen, or 

 worker — transmits the very same 

 genetic complex, including factors for 

 racial dilTerences in color, form, and 

 instinct, and the genetic potentiality of 

 producing male, queen or workeraccord- 

 ing to conditions. A simplex genetic 

 assortment produces a male, a duplex 

 produces a female, — a queen in case of 

 royal feeding, a worker in case of 

 worker feeding. 



THE PHYLOGENETIC POINT OF VIEW 



Let us consider the matter now from 

 the point of view of phylogeny. What 

 has caused the complicated instincts of 

 the workers to be developed and what 

 maintains these instincts at their pres- 

 ent high level? In a word, how has 

 natural selection acted upon the repro- 

 ductive castes so carefully guarded 

 and cared for by the workers? 



For the one brief marriage flight of 

 her life the queen must have strong 

 wings to fly and keen senses to observe 

 landmarks so that she may return to 

 her hive. Failing in this one test she 

 loses all chances of posterity. More- 

 over her mate must be superior to his 

 fellows in speed of wing and sureness of 

 vision. The marriage flight is indeed a 

 eugenic test and selection of the supe- 

 rior male. Germ plasm then of queen 

 and drone must bear factors for supe- 

 rior sensory apparatus and strong wings 

 and muscles. 



But the germ plasm of the royal pair 

 must carry factors also for industry in 

 collecting honey and pollen and in con- 

 structing combs and caring for the 

 young or the colony as a whole will fail. 

 Relatively high fertility must also be 

 present for scarcity of eggs would 

 result in small numbers of workers and 

 scarcity of sperm would result in failure 

 of fertilization giving excess of drones. 



Natural selection acts upon the 



colony as a unit, and the character of 

 the colony is genetically determined by 

 the queen mother and her mate. The 

 hive having greater industry, more 

 socialized instincts, stronger wings and 

 keener senses will survive under ad- 

 verse conditions, show better capacity 

 for adaptation, and thus have greater 

 chances of posterity. 



THE PHYSIOLOGICAL POINT OF VIEW 



Finally from the physiological point 

 of view there are numerous interesting 

 problems concerning the differentiation 

 of the castes. 



It may be supposed that there are 

 factors located in the various chromo- 

 somes tending to pull the course of 

 development in the female direction. 

 These would have a tendency to sup- 

 press male characters, both primary 

 and secondary, but would stimulate 

 the development of embryological fun- 

 daments of female characters. These 

 factors are, however, too weak to act 

 unless doubled, and hence the simplex 

 condition produces a male, the duplex 

 a female. 



Queens and workers, although simi- 

 lar genetically, are distinct before they 

 have had experience with the outer 

 world. Differentiation is therefore 

 due, not to active experience, but to 

 feeding. A comparison may be made 

 here with a situation in poultry. If 

 ovaries be removed from a pullet, male 

 form and plumage are developed, as 

 well as male instincts, voice, etc. Now 

 the effect of worker food in bees has 

 been degeneration, or rather failure of 

 development, of the ovaries. The 

 queen may then be compared to the 

 normal egg-laying hen, while the worker 

 may be compared to the hen with 

 ovaries removed, possessing characters 

 that are normally suppressed by ovarial 

 activity. 



EGG-LAYING WORKERS 



Intergrades between sexual and 

 worker castes normally occur in bum- 

 ble-bees, and in the honey bee, inter- 

 grades, such as egg-laying workers, are 

 not unusual. Worker larvae, develop- 

 ing near queen cells, obtain royal jelly 



