160 



rs rcv/E. 



[Febriiary^Mnrch 1SS9. 



Panorpa debilis VVestw?, and Bore7is 

 callfornicus Pack. — Having thus be- 

 come in a degree familiar with the or- 

 gans so clearl}' described and figured 

 by Will, I was prepared to look for 

 them in other insects. It was not until 

 I had found them in the epipharvnx of 

 Panorpa and Bore?(s, that I was awai-e 

 that other obser\ers had ah-eady noticed 

 them. In his historical summary Will 

 states that G. Josepli - in 1S77 men- 

 tions that in almost all orders of insects, 

 but especially in those living on plants, 

 we find at the base of the tongue, in the 

 region of the throat and the palate, little 

 cujDS, which sliould be regarded as or- 

 gans of taste. Kiinckel and Gazagnaire^ 

 (1881) found in Vohicclla similar or- 

 gans on the paraglossae (labella), on 

 the end of the epipharynx and at the 

 beginning as well as throughout the 

 whole extent of the pharynx. Will does 

 not seem to have seen the elaborate 

 plates of these authors in the second part 

 of their great work on Volucella, where 

 the mouth-parts of Volncclla'^ are beau- 

 tifully figured by Gazagnaire with nu- 

 merous figures of microscopic sections of 

 the proboscis and of the epipharynx and 

 hypopharynx, including excellent histo- 

 logical details showing the gustatory 



^Joseph, Gust. Zur morpliologie ties geschniacksoi- 

 ganes bei insekten. ( \mtlicht;i- bericht der 50. Ver- 

 sanimlung deutscher naturforscher u. Arzte in Miin- 

 clien, 1877, P- 227-22S.) 



:! Du ,sidg:e de la gustation cliez les insoctes diptcres. 

 Constitution anatomique et physiologique de I'epipha- 

 rynx et 1' hypopliaiynx. CCoinptes rendus, 1881, v. 95, 

 P- 347-3SO-) 



4 Reclieiches sur Porganization et le developpe- 

 ment des dipt&i-es et en parliculaire des vohicelles de 

 la faiiiille des syphides, part i, 1S75, part 2. 1S81. only 

 the plates and their explanations. 



cups, cells and nerves. The taste-cups we 

 have seen in the insects mentioned be- 

 low are similar to those figured by Gaz- 

 agnaire, and, judging by their appear- 

 ance and position where the fluids en- 

 ter the mouth, there seems little doubt 

 that these pits or cups, with their pro- 

 jecting rods or fine setae are true organs 

 of taste. 



Our own observations are very super- 

 ficial, no attempt having been made to 

 study the parts histologically, or by micro- 

 scopic sections, so as to work out the 

 nerves and ganglion cells. We have 

 simply dissected out the parts, placed 

 them for a few minutes in a mixture of 

 carbolic acid, i part, and oil of turpen- 

 tine 4 parts, with a drop or two (jf dilute 

 liquor potassae. This clears the parts, 

 rendering them transparent, so that they 

 can be at once placed in the animalcule- 

 box and examined under the microscope. 



A word or two as to the homologies 

 of the epipharynx may not be out of 

 place. Little attention has been paid to 

 the nature of this organ, and it is most 

 desirable that a careful and comparative 

 study of it be made. Morphologically 

 it is the pharyngeal lining of the labrum 

 and clypeus. and seems to be present in 

 all insects. In the higher lepidoptera 

 (macros) what has been regarded as 

 the labrum is called by Dr. A. Walter^ 

 the epipharvnx. In the hymenoptera it 

 forms a short fold situated under the pro- 

 jecting labrum. What in the mecaptera 



•i Walter, Alfred. Beitrage zur niorphologie dcr 

 schmetterlinge. lertheil. Zur niorphologie der schniet- 



terlingsnuindthcilc. (Jena, zeitsclir., 1885, v. iS, n. s., 

 v.Q.)^ 



