38 



SCIENCE-GOSSIP. 



confined to the underside of the hind-wings. Argyiiiiis 

 la/ona is perhaps the best-marked and most beautiful 

 example. In a few species of this genus, among 

 which are A. paphia and A. pandora, the silvery 

 markings take the form of stripes. Metallic 

 submarginal lines are sometimes formed on the 

 undersideof the hind-wings in the genus Coenonyiiipha. 

 Among the Hesperidae, the genus Cartej'ocephalus 

 affords examples of distinct silver spots in three 

 Palaearctic species, C. argyrosiigiiia, C. gemmatiis, 

 and C. chrislophi. The discoidal spot on the 

 underside of the hind- wings of several species of 

 Colias is often distinctly silvery. 



The W'ings of butterflies when at rest are mostly 

 brought together over the back, except in the 

 Hesperidae where the fore-wings are flexed in a 

 downward direction as in most Heterocera. 

 (c.) Abdo.men. 



The last division of the body is the abdomen, con- 



sisting of nine segments (a — /). It is elongated, but 

 not beyond the outer margin of the hind-wings in any 

 Palaearctic species. In the Papilionidae the inner 

 margin of the hind-wings is cut away, as it were, to 

 allow freedom of movement. In all other families 

 the portion of the wing on either side, between the 

 internal nervure and the inner margin, is everted ; so 

 as to form a channel or groove in which the abdomen 

 rests. The abdomen is most frequently of the same 

 colour as the thora.x ; and generally dark brown or 

 black, but sometimes of the prevailing colour of the 

 wings as in many of the Lycaenae. It is usually 

 clothed with hairs, sometimes densely so, as in 

 Parnassius and Vanessa. The last segment contains 

 the genital armature, and in some genera, as in 

 Ltiedorjla and Parnassius, the female exhibits a 

 curious pouch-like appendage, the origin and use of 

 which is unknown. 



(To lie continued.) 



INSTINCT. 



By R. Dickson-Bryson, B.A., F.P.S., F.R.As.S. 



[Conti/nted J^f-oni page 12.) 



In Ants. 



■VT O . other insects display so much versatility in 

 •^ ' their habits as the ants. Like bees, they are 

 social, and the colony is composed of individuals of 

 different natures. While the general plan of the bee- 

 hive is unique, the domicile of ants is distributed into 

 several departments, according as the ants are 

 carpenters, miners, or masons. These departments 

 have not the elegance and the regularity of the hive, 

 but they are of ample capacity and convenient 

 arrangement. An amazing skill is shown in the dis- 

 position of the materials of construction, so as to 

 secure complete stability. In the erection of arches 

 the ants display as much skill as our ablest engineers. 

 The most varied materials serve their purpose, such 

 as grains of wheat, blades of grass, fragments of 

 wood, and the remains of slaughtered insects. Not 

 anything is despised, provided the shape, dimensions, 

 and rigidity are suitable. Frequently they modify 

 their processes and take precautions which seem to 

 show that they are not under the absolute sway of 

 instinct. Only the wood ants in this country employ 

 ' the several materials enumerated. The black ants do 

 not use anything but earth, of which they make the 

 pillars and walls of their dwelling. The carpenter 

 ants saw, plane, and polish the wood required for 

 their purposes. These miniature planks are about the 

 thickness of a visiting card. The building operations 

 of the three species are carried on in stages. 



Ants are underground dwellers, and they con- 

 gregate in vast numbers to perform their several 

 ta.sks, but notwithstanding their inter-communal 

 habits, they neither borrow nor imitate. Each 

 performs its own work^ efficiently. This is all the 



more remarkable, seeing there is little or no> 

 difference in their size, or in their instruments of 

 construction. The merely organic differences so 

 far as we know them, are inadequate to explain, 

 the anomal)'. It is clear that instinct is neither 

 modifiable nor transmissible, even among allied 

 species. They are very devoted to their young, and. 

 fondle them with all the affection of which they are 

 capable. They wash, feed, and in good weather 

 lead them out for airings. If, during these excursions, 

 any danger threatens, they seize them in their 

 mandibles and carry them, off without hurt. The 

 bodies of these young ants, be it remembered, are 

 delicately soft, while the mandibles of the parent are 

 hard, sharp, and formidable, yet the young are held 

 in position without the slightest injury. 



Ants evince a marked taste for the liquid produced 

 by various aphides, or plant-lice, and their manner of 

 treatment of the aphides to secure this coveted liquid is 

 worthy of note. They have well-organised aphis, 

 hunts, setting out in vast hosts to explore the country 

 in their vicinity. When they have found the object 

 of their search they introduce themselves with the 

 most bland winsomeness. Once in their possession, 

 they take every care of the aphides, and woe to the- 

 intruder that would interfere. 



Examine a tree infested with aphides and you will 

 probably discover a number of ants running along its 

 length. Observe them closely and you will be the 

 witness of an interesting manoeuvre. An ant 

 cautiously approaches the aphis, and gently intimates. 

 its presence by drawing its antennae along the back. 

 This appears to be a flattering mode of treatment, and 

 one that cannot be resisted by the tiny aphis. Soor^ 



i 



