2IO 



NATURE 



[June 2;, 1895 



order, and lends weight lo the view that they are useful chiefly for 

 near \'ision and in dark places. The compound eyes are prominent 

 and adjustable in proportion as they areof serWce to the species, as 



Fig. I. MS in Instcl^: a, wnc ctumciu cf cjc of cockro.icli (after Grcn.iclicr) ; li, 



* diapt n of compound eye in insect (after Miall and Denny); c, organs of 



smell -ha (after Kr.-iepclin) ; d, a, b, senscorgans of abdominal appendages of 



ChrysopiU ; t, small pit on termin.al joint of palpus in IVrIa (after Packard): •-:. diaKr.am 



of sensory ear of insect (after .Miall and I>cnny) ; f, auditory apparatus of Meconenia ; a, 



r.r-- lili.i ..f ihis locust;^, diagrammatic section through same (after Grabcr) ; o, auditory 



■'^'-■nus. seen from inner side, showing tympanum, auditory nerve, terminal 



■id opening .and closing muscle of same, as well as muscle of tympanum 



I .raber). — .Ml very greatly enlarged. 



witness those of the common house-fly and of the Libellulid^e or 



dragon-flies. It is obvious from the .structure of these compound 



eyes that impressions through Ihcm must l)e 



ver)' different from those received through 



our o»-n, and, in pf)int of fact, the experi- 



menial researches of llickson, Plateau, TtKrke 



and Lemmcrmann, I'ankrath, Kxner, and 



\'iallancs have practically established the fact 



that while insects are shtirtsighled and |>cr- 



rcive slationar)' ol>jects im]H.rfcctly, yet tlieir 



compound eyes arc letter filleti than the 



vertebrate eye for apprehending objects set 



in relief or in motion, and are likewise 



keenly sensitive to colour. 



.So far as experiments have gone, they .show 

 that insects have a keen colour sense, though 

 here .igain iheir .sensations of colour are 

 rliffereiit from those prrKluced u|X)n us. 

 Thus, as Lublxick has shown, anis arc ver)- 

 .sensitive to the ullra-violet rays of the spec- 

 trum, which we cannot |K-rceive, though he 

 was led lo conclude that to Ihe ani the 

 general a.spcct of nature is jiresenled in an 

 aspect very different from that in which it 

 appears to us. In reference to Itees, I he 

 experiments of the same author prove clearly 

 that they have this sense of colour highly 

 dcvclopcfl, as indeetl might lie expected 

 when we consirler the |>art they have played 

 in I' I iient of flowers. While these 



c^l in lo show that blue is the 



!>«••<- '■ iiijour, this does not accord 



with Albert .Miiller's ex|x-riencc in nature, 

 nor with the general exjierience of apiari.ins, 

 who, if asked, would very generally agree 

 that Ix-es show a preference for white flowers. 



Touch. — The sense of touch is supposed 

 lo rnide chiefly in Ihe anlenn:e or feelers, 

 though it rerjulres bul the simplest oltscrva- 

 lion lo show ihal »iih sofilKHJieil insects the sense resides in 

 any |>ortion of the b xly, very much as it docs in other anim.il.s. 



NO. 1339, VOL. 52] 



In short, this is the one sense which, in its manifestations, may 

 be conceded to resemble our own. ^■et it is eWdently more 

 specialised in the maxillary and labial jxtlpi and the tongxie than 

 in the antcnnx in most insects. 



Tast,\ — \ety little can l>e positively proved 

 as to the sense of taste in insects. Its exist- 

 ence may be confidently predicated from the 

 acute discrimination which most monopha- 

 gous species exercise in the choice of their 

 ftxxl, and its location m.iy be assumed to be 

 the mouth or some of the special trophial 

 organs which have no counterpart among 

 vertebrates. Indeed, cert.iin pits in the 

 epipharjnx of many mandibulate insects and 

 in the ligula and the niaxilhv of lx;es and 

 wasps are conceded by the authorities to be 

 gustator)'. 



Smell. — That insects possess the power of 

 smell is a matter of common observation, 

 and has been experimentally proved. The 

 many experiments of I.ubbork upon anis left 

 no doubt in his mind that the sense of smell 

 is highly developed in them. Indeed, it is 

 the acuteness of the sense of smell which 

 attracts many insects so unerringly to given 

 •ilijects, and which has led many persons to 

 believe them sharp-sighted. Moreover, the 

 innumerable glands and special organs for 

 secreting odours furnish Ihe strongest indirect 

 proof of the same fact. Some of these, of 

 which the osmaterium in Papilionid larvx 

 and the eversible glands in I'aroigyia are 

 conspicuous examples, are intended for pro- 

 tection against inimical insects or other 

 animals ; while others, possessed by one only 

 of the sexes, are obviously intended to please 

 or attract. A notable development of this 

 kind is seen in the large gland on the 

 hintl legs of the males of some sjiecies 

 of Ilepialus, the gland being a modification of the tibia, 

 ant! sometimes involving the abortiim of the tarsus, as in the 



2.— -Sensory Orsan* in Inuct't : 



sensor)' piis on aiitcnnn: of younu winKlc--s Aphis f^rrsi- 

 ctrnigcr (after Smith) ; n, urgan of smell in May ln-cilu (after Mauser); c, oryaii of smell 

 in V'c^pa (after Hauscr) ; i>, %cnsor>' organs of Ttrnifs flai»if*ts ; a, tibial auditory organ ; 

 tr, cnlarRcmcnt of same ; b, sensory pits of tarsus (after Stukcs) ; li, organ of ta-stc in maxilla: 

 of I'cifta 7' u/e-ari J (nUcr Will) ; F, organ of taste in laiaum nf same insect (after Will) ; <;, 

 organ of smell in Caloplcnus (after Hauscr) ; M, sensory pilose depressions on tibia of Termcs 

 (after Sioke*) ; t, terminal portion of antennn; of Myrmica ru^inodt's : c, cork-shaped organs ; 

 J, outer sac ; /, iiilw ; w. posterior chaml>cr (after Lubbock) ; K, longiluflinal section through 

 portion of flageltum of antenna: of worker bee, showing Mnsory hairs and supposed olfaclorj" 

 organs (after Cheshire). All vcr) greatly enlarged. 



Kuropcan ff. hectus (L.) and our own H. ^r-Arcwj/'IStrctch.) Thi: 

 posiicssion of odorifcrous'glands, in other words, implies the pos- 



