14 Transactions of the Society. 



we now remove tlie spermatheca and its conduit and glands from the 

 common oviduct, and examine by a ]/2 in. in glycerin, we may bring 

 the difierent parts of fig. 7 into view. The appendicular gland m g 

 much resembles in structure that of the bee, but here close 

 similarity ends. The spermatheca, about 4 mm. in diameter, has no 

 investing coat of trachea?, but is surroimded by four layers, ahc d, 

 the outer three of which are full of air-tubes, 1 1, fig. 7. The 

 membrane forming the sac is exceedingly delicate ; outside this the 

 structure appears secretive while the next is elastic, the whole 

 being protected by a very wrinkled membrane. By pressure the 

 spermatozoa may be driven through the duct e, and in their 

 passage they are accompanied by mucus containing minute oil- 

 globules. The spermathecal duct is joined at y by the appendicular 

 gland-duct. The common duct now enters and becomes central 

 to the curiously formed body, which is clearly homologous with 

 that in the bee, marked 1 1, fig. 5 ; the muscle h i, fig. 7, 

 appearing to answer to (/, fig. 5, while / and ph, fig. 7, are 

 homologous with //, fig. 5. The nerve-threads uniting the several 

 parts in the bee seem here to be in part represented by the 

 numerous fibres n, fig. 7, running between the elastic and secretive 

 coats, and the controlling muscles of the valve. These nerves 7i 

 are not so exposed as would be judged by examining the figure, 

 since the large ganglion which has been removed by dissection 

 afibrds them every protection. The structure is clearly far less 

 developed than that we previously examined, as here the duct 

 seems simply closed by the contraction of the muscles at / and p> h 

 to prevent spermatozoa passing, the same muscles relaxing, allowing 

 the duct to open, possibly under pressure brought to bear upon it by 

 the elastic coat of the spermatheca itself. This greater simplicity 

 answers completely to the habits of the insects we are considering.* 

 In wasps the ability to produce fertilized or unfertilized eggs in 

 rapid alternation is not necessary as it is with bees. 'J here is 

 abundant evidence that queens amongst the latter insects choose 

 the cells in which they deposit eggs, at one time avoiding and 

 at another searehiug out every drone cell, but this seems to be 

 simply that workers or drones may be produced as the honey-yield 

 and condition of the colony demand, for observation also shows that 

 a queen can take cells pretty much as they occur, and adapt the 

 egg at once. Amongst wasps, on the contrary, the production of 

 males appears almost entii-ely a question of season, these being 

 raised in a brood-batch to eflect the fertihzation of those females 

 that are to hibernate. The accuracy and certainty with which 

 this operation of fertilization can be accomj)lished by the queen- 



* The fertile (uuimpregnated) woikers amongst wasps only produce males, 

 and all the facts of the case point to the production of males by queen wasps frouj 

 unfertilized eggs. 



