224 



HARDWICKE'S SCI EN CE- GOSSIP. 



THE Y-SHAPED ORGAN OF PAPILIO 

 LARV^l. 



MR. CLIFEORD, in his interesting notes on 

 Homed Caterpillars (p. 193), cites the state- 

 ment of Bonnet, " that a caterpillar of Machaon, 

 •which he touched, directed the horn towards the 

 lingers, as if to strike." He adds, "Other observers 

 have not as yet confirmed this." Permit me to 

 confirm it by a collateral observation. 



Erom an Entomological journal which I kept in 

 Newfoundland, in the year 1S35, 1 extract the fol- 

 lowing notes on the larva of Papilio Asterius, a 

 species closely allied to our Machaon. "From the 

 very first ring of the body, just at the back of the 

 head, there proceeds a soft, flexible, forked organ, 

 of an orange colour. I have seen it protruded to 

 the length of three-quarters of an inch. At about 

 one-eighth of an inch from the base it divides into 

 two branches, each curving outwards, and tapering 

 to a blunt point. This organ is usually drawn in, 

 and quite concealed within the neck ; and the cater- 

 pillar protrudes one branch or both, at pleasure. I 

 have watched the parts at such times, and have 

 observed that two transverse lips appear to open in 

 the neck, and the fork is thrust out, not the points 

 first, but the base ; the whole structure being turned 

 inside-out. I am convinced that its use, or at least 

 one of its uses, is as an instrument of defence ; lor, 

 on my touching the side of the caterpillar — the left 

 side, for instance— it would jerk round its head 

 towards the place, and protrude the left division or 

 branch of the Y ; on my touching the right side, it 

 would thrust out the right branch, keeping the 

 other in. The operation was always accompanied 

 by a strong foetor, like the odour of parsnip — the 

 plant on which the larva feeds ; it left a slight 

 wetness on any object touched. Often, when I 

 suddenly opened the box in which I was rearing 

 these caterpillars, they would thrust out both 

 branches of their Y-organ, with a gush of the 

 odour ; and then, in a few seconds, gradually draw 

 them back by involution." 



The larva of Papilio Turnus, a companion species 

 to the one I have just named, throughout the 

 Atlantic regions of North America, from New- 

 foundland to Alabama, possesses an organ of 

 exactly similar structure, and uses it in an exactly 

 similar way. So does that of P. Philenor, a beau- 

 tiful species, of the Southern States. Of all these 1 

 speak from personal observation ; but I have little 

 doubt that the organ is common to the entire genus 

 of Papilio as restricted. 



Doubleday, in his beautiful work, " The Genera 

 of Diurnal Lepidoptera," limits his notice of the 

 organ to the technical diagnosis of the family 

 Papilionida, and those of the two genera, Omitho- 

 ptera and Papilio. In the former he says, " The 



larvae arc furnished with two retractile tentacula on 

 the prothoracic segment, which are extended when 

 the animal is irritated, and then exhale an aromatic, 

 but mostly disagreeable, odour." In the diagnosis 

 of Papilio he merely defines the tentacula as 

 " without any external sheath," thus distinguishing 

 the genus from Ornithoptera. Taking no notice of 

 the familiar European and North American species, 

 he singles out the rare P. Ilippason of Guiana, of 

 which he says, "If we can trust to Stoll's figure,, 

 the prothoracic tentacula or osmateria are largely 

 developed." 



I am not without hope, therefore, that these little 

 notes of mine, which have lain for six-and-thirty 

 years within the leaves of my portfolio, may con- 

 tain a contribution, even though trifling, to 

 knowledge. 



Torquay. P. H. Gosse, F.R.S. 



MONOTREMATA. 



CERTAIN four-footed beasts which were at one 

 time ranked among the Edentates, or toothless 

 animals, are now — for good and sufficient reasons, 

 founded on structural peculiarities— included in a 

 separate order under the above name. Among them 

 is the Australian Hedgehog (Echidna), which is 

 furnished with a coat consisting entirely of stiff 

 bristles. Its affinity with the European Hedgehog 

 is of the most superficial kind. Without going into 

 anatomical details, it may be mentioned, that 

 whereas the Hedgehog is furnished with a mouth- 

 ful of sharp teeth, Echidna can boast only of a few r 

 hard points in the back of the jaw as the sole 

 representatives of those very useful appendages. 

 The mouth itself is prolonged into a tubular beak, 

 which is equally serviceable in its way ; for within 

 this beak lies concealed a long tongue, which can be 

 protruded three or four inches beyond its sheath, 

 and is provided with glands capable of secreting a 

 thick viscid fluid. Termites, ants, and "such 

 small deer" form the food of Echidna: these it 

 hunts out with the aid of its long snout, which is 

 constantly at work " rummaging " in the debris cf 

 the forest. Backwards and forwards, in and out, 

 goes that pitiless tongue, each time clothed with a 

 fresh supply of glutinous matter from the glands 

 at its root, and each time drawing in a host of 

 victims clinging helplessly to its sides and point- 

 Of necessity, Echidna takes in with its food a large 

 amount of dirt, stones, and fragments of wood ; 

 indeed sometimes the stomach is half filled with 

 such matters. With all this, it possesses wonderful 

 powers of abstinence. " One in the possession of 

 Messrs. Quay and Gainard refused all sustenance 

 for a month after its capture, without appearing to 

 suffer in its general health, though it became 

 thinner."— P. H. Gosse, Intr. to Zool. 



