7820 Insects. 



which the blacl;-slriped snail finds a shelter. These snails frequently make their way 

 through the lattice window into the dairy shelf, where the meat is kept, and I have 

 frequently found them feeding on raw beef. Mr. Curtis has remarked this liking of 

 Limax ma.ximus for flesh. — /. Hanson ; York. 



Economy nf Apatura Iris. — Dr. Maclean, to whom I am indebted for the early 

 history of this lovely butterfly, watched a female deposit two eggs on the upper side of 

 two leaves of Salix Caprasa (the sallow), on the 16lh of July: the egg somewhat 

 resembles a fossil Echinus which has lost its spines. One of these eggs the Doctor 

 took home, and it hatched on the 25th of July, just nine days after it was laid ; the egg 

 left on the leaf where its parent had deposited it hatched ou the 2Sth of the same 

 month, having been in the egg state twelve days. The little larv£e are of a dark browu 

 colour: on the eighth day after being hatched they change their skin, and then are 

 furnished with two horns or processes, att;\ched to and forming part of the head ; and 

 it is curious that now, on the first appearance of these horns, they are proportionally 

 larger and longer than at any other period of the creature's larval life. With this first 

 change of skin the larva loses every tinge of its original brown colour, and becomes 

 exactly of the same hue as the sallow-leaf on which it feeds : a portion of the leaf is 

 consumed every day, but the mid-rib is left intact ; and the little creature, when 

 resting from its alimentary labours, climbs to the denuded bristle-like tip of this mid- 

 rib, and there remains perfectly molionless, with the anterior extremity raised as we 

 see it in the larva) of Sphinx Ligustri and Dicranura vinula. Dr. Maclean's larva 

 continued this mode of life until the 15th of November, when it descended from the 

 leaf, and, covering with silk the rind of the twig immediately below the attach- 

 ment of the leaf, grasped this web firmly with its claspers ; stretched itself out at full 

 length, with its horns porrected before it, and thus settled itself down to endure the 

 winter's cold and the winter's storms. This is always the case; its modus operandi is 

 the same whether in a state of nature or in the vivarium of an entomologist. Instinct, 

 that infallible and inscrutible guide, tells the unreasoning larva that dehiscence of the 

 leaf-stalk will take place after the first frost, and that the leaf will fall to the ground : 

 the leaf does fall, but not until its falling is a matter of indifl'erence to the larva; not 

 until the larva has aitaihed itself so firmly to the twig thai neither wind nor rain cau 

 remove it. In the ensuing spring, the same influences which compel the sallow to 

 throw out new twigs and new leaves, also resuscitate the torpid or dormant larva ; its 

 eating propensities are aroused, and it feeds greedily until the period of its first meta- 

 morphosis has arrived. The full-grown larva somewhat resembles a slug in shape, and 

 a sallow-leaf in colour ; the head is. of a very peculiar form, each of the lateral divi- 

 sions being prolonged on the crown into a kind of horn slightly inclining outwards; 

 these horns are green, darker and almost black at the tips, and the space between them 

 is of a pale yellow colour, approaching to white, but there is a pointed triangular green 

 plate above the mouth, which enters into and almost divides the yellow part: the body 

 is green, stoutest in the middle, and lapeiing to each end, hut mostly towards the tail, 

 where it terminates in two sharp points, ])arallel, closely approximate and directed 

 backwards : on each side is a narrow yellow stripe traversing the region of the 

 spiracles, and extending the entire length ; and besides this there are seven oblique 

 yellow stripes on each side, all of tliem commencing near the straight lateral line 



