1881.] 



MICKOSCOPICAL JOITKNAL. 



14T 



tion to our knowledge of the parts. 



Running the scalpel from the base 

 of one mandible back, across, close to 

 the neck and forward to the other 

 mandible, remove the brain and sali- 

 vary glands ; cut the oesophagus as 

 far forward as possible, turn it back, 

 and if all has been done carefully, 

 one sees coming from the thorax the 

 spiral ducts of two glands, which will 

 be found, on following back, lying 

 one on each side of the oesophagus, 

 in the space between the muscles of 

 the wings. 



At the base, the duct enlarges into 

 quite a reservoir. The ducts unite 

 within the neck, or just as they enter 

 the head, and, following the floor of 

 the latter, are joined by a pair com- 

 ing in right and left. Following up 

 one of these side glands, we find it 

 dividing into three main branches, 

 ultimately terminating in glands ; the 

 glands from the thorax bear a strik- 

 ing resemblance to the Malpighian 

 tubules of insects, while those from 

 the head are larger, different in shape 

 and composed of much smaller cells. 

 Keeping to the floor of the head, the 

 main duct passes on to the sub-men- 

 tum. Here, on joining the spiral 

 tube coming from the ligula, it passes 

 by an opening common to both into 

 the mouth. Below the opening the 

 spiral tube dips into the mentum and 

 is imbedded in its muscles. 



A series of cross sections shows it 

 to gradually widen to near the base 

 of the ligula, where it terminates in a 

 chamber that leads above into the 

 sac, and below by a valvular opening 

 into the groove in the rod. 



Thus we have a passage from the 

 tip of the ligula through the groove 

 in the rod, and the spiral tube in the 

 mentum to the opening in front of 

 the pharynx, above the labium and 

 between the mandibles. This open- 

 ing is transverse, and seems to have 

 lips, and from its appearance we 

 should expect it to close like a valve, 

 if suction was applied below. 



Meeting this tube from the ligula, 

 and discharging its contents through 



the same opening into the mouth, is 

 the spiral duct from the glands of the 

 head and thorax. 



The questions are at once thrust 

 upon us, whence comes this structure? 

 and of what use is it to the bee ? If I 

 were wise the article would end here ; 

 but our inclination to explain every- 

 thing by resorting to speculation, is 

 always strong, in the absence of facts 

 to curb it. It seems but natural from 

 the size, position and outlet of the 

 glands, connected as they are with an 

 inlet for the nectar of flowers, to con- 

 clude that they are organs that fur- 

 nish the animal secretion that changes 

 nectar into honey, and I would ven- 

 ture the suggestion that they may be 

 the spinning glands of the larvse mo- 

 dified. If this is true, I should ex- 

 pect to find them either in an active 

 or aborted condition in nearly all 

 Hymenoptera. 



Another question raised is, in what 

 way is nectar carried from the flower 

 to the mouth ? This must be, from 

 the nature of the case, largely a mat- 

 ter of speculation. Prof. Cook, in 

 his article, says : " The tongue is also 

 retracted and extended rythmically 

 while the bee is sipping." May not 

 this motion be due to a pumping 

 action of the grooved rod of the li- 

 gula, that enlarges and diminishes the 

 size of the sac lying behind it ? It 

 would seem that the bee has perfect 

 control of this rod, that it is remark- 

 ably elastic, and capable of much ex- 

 tension and contraction ; the rod 

 and sac thus acting as a suction and 

 force pump, as will be easily under- 

 stood by one familiar with the parts. 



Of course I cannot say that the 

 bee makes this use of it, but I do say it 

 should, and if it does not, it is pure 

 stupidity on its part. And if some 

 one demonstrates that I am all wrong 

 novv, evolution at no distant day will 

 set me right, for there will be born a 

 bee, less conservative, that will dare 

 defy old usages, and take a new de- 

 parture ; that bee, trust me, will make 

 use of this cunningly-devised appara- 

 tus, and produce honey cheaper than 



