THE ORGANS OF THE SENSES. 299 



197. 



The tongue is always the organ of taste where present. We have 

 seen above that many insects, namely, the Orthoptera, Libellulee, the 

 majority of beetles, many Hymenoptera, and, indeed, all mandibulate 

 insects, possess a more or less distinct tongue ; we have but to ask, 

 may we consider this tongue as the organ of taste ? Taste can be of 

 importance only to such animals as feed upon a variety of substances 

 and masticate them. In haustellate insects this is not the case ; they 

 always subsist upon one and the same food, and generally inhabit what 

 they feed on, and consequently less require this sense. Indeed, they 

 are wholly deficient in a fleshy tongue, which can alone taste, and when 

 present as stiff setae, taste cannot be spoken of. But that the fleshy 

 tongue which we find in the Libellulee and grasshoppers is certainly an 

 organ of taste, is corroborated by its delicate and soft superior surface, 

 its greater abundance of nerves, and, lastly, the various nature of their 

 food, which is visibly slowly masticated, and furnished with saliva 

 from the mouths of the ducts of the glands lying beneath the tongue. 

 To these we may add the wasps and bees, which suck the honey of 

 various flowers by means of their tongue, which is provided at its apex 

 with distinct glandular points, that, besides the business of ingestion, 

 serve doubtlessly to taste and distinguish the various kinds of honey. 

 This may also doubtlessly be maintained of the in general soft 

 membranous tongue of the Staphylini. Some physiologists, for 

 example, Rudolphi, deny the sense of taste to insects ; others seat it 

 in the palpi, where it certainly does not belong ; and others, again, 

 Straus, for instance, discover it in the tongue, where it is doubtlessly 

 to be sought, and frequently sufficiently distinctly exhibited. The 

 abortion of the tongue in many mandibulate insects ought not to 

 surprise us ; its cause, as well as the abortion of the organ of smell, is 

 the preponderance of the function of respiration, as the tongue is like- 

 wise a humid organ, for, in insects, every organ, by reason of the 

 universal distribution of air in them, has a tendency to become dry and 

 horny. In this they again find their parallelism in the birds, whose 

 tongue is small, imperfect, almost cartilaginous, indeed frequently 

 (Pteroglossus} perfectly horny, and resembling a feather, exactly 

 like the tongue of many beetles, for example, the Capricorns, in 

 the internal organs of which there is a strong disposition to become 

 horny. 



