328 Dr. E. A. Cockayne on 



nucleus of a single spermatozoon and gave rise to the male 

 portion of the gynandromorph, the other half developed 

 parthenogenetically and gave rise to the female portion. 



In his second paper, in 1907, Morgan reiterated his 

 theory, and in support of it brought forward Toyama's 

 gynandromorphous Bombyx mori. 



The larva of this insect was striped on the left side, and 

 the imago was female on this side; the right side of the 

 larva was plain and of the imago, male. The striped con- 

 dition of the larva is a Mendelian dominant over the plain. 

 Morgan regards the striped female half as being derived 

 from the combination of a spermatozoon carrying the 

 recessive " plain " character with an ovum carrying the 

 dominant " striped " character, and the plain male half 

 as being formed from another spermatozoon, which entered 

 the egg and developed without any fusion with the nuclear 

 substance of the egg. 



Boveri's hypothesis rests on the condition met with in 

 the gynandromorphs of the Eugster hive of bees. In these 

 insects Newell has shown by the following experiments 

 that drones inherit the characters of the queen. An Italian 

 yellow queen crossed with a Carniolian grey drone produced 

 yellow workers and queens, and the drones were yellow 

 also. A Carniolian grey queen and an Italian yellow drone 

 produced yellow workers and queens, but the drones were 

 grey. This shows that yellow is dominant over grey, and 

 that drones are produced from unfertilised eggs, and derive 

 their characters from the queen or female parent only. 



Boveri carefully examined some of the Eugster gynan- 

 dromorphs preserved in spirit, and in spite of the loss of 

 colour he made out that the male parts were maternal and 

 the female parts paternal in their characters. The colour 

 of the male parent was dominant over the colour of the 

 female parent. 



Mehling made an independent examination of the 

 material and arrived at the same conclusion. The condi- 

 tion found in these bees supports the view that the male 

 parts are derived from the unfertilised part of the ovum, 

 the female from the fertilised part. Another hive of bees 

 has recently been met with at Terek-Gebiet in the Northern 

 Caucasus, and has produced many gynandromorphs, some 

 of which are halved. They were the offspring of an Italian 

 queen by an unknown drone, probably of the form known as 

 Apis mellifica remipes. These gynandromorphs, according 



