'33 



HARD IVICKE ' S S CIE NCE- G O SSI P. 



of the atmosphere shrivelling up the ruptured skin or 

 epidermis ; and, sometimes at least, enters into the 

 pupa state on the upper surface of the leaves of the 

 food-plant. After casting its skin, the larva is of a 

 uniform pale yellow colour entirely : the head, limbs, 

 branched spines, anal appendages, and the ventral 

 tube, as well as the body, are all of this uniform pale 

 yellow colour, while the elevated spiracles are white, 

 the exuviae having obviously been shed from all these 

 parts. The cast skin is run up together into com- 

 paratively little bulk, is passed over the extremity of 

 the body and transferred to the anal appendages, the 

 flexile ventral tube being used in pressing it forwards 

 against the fecal canopy ; and with its head, flank'ng 

 limbs, and a complete chevaitx-de-frise of spines, 

 constitutes a new, larger, and most efficient platform 

 for the reception of the faeces. In a short time the 

 creature in all its parts assumes the normal hues. 



When full-grown, and about ready to lay itself up 

 prior to assuming the pupal condition, the larva 

 throws off the fecal canopy, and takes a meal or two 

 more ; then it stretches itself out horizontally, retracts 

 the two segments of the telescopic ventral tube until 

 the basal and larger one is much shortened and the 

 apical one so invaginated and withdrawn within the 

 basal that only the tip projects beyond it, the anal 

 appendages being now erected perpendicularly ; whilst 

 the head and limbs are drawn up closely to the under 

 surface of the body, the head being deeply sunk into 

 the tissues, and the limbs directed backwardly as well 

 as being somewhat drawn together and sunk ; and 

 the anteroinferior portion of the abdomen (embracing 

 the first three segments) is pressed down firmly upon 

 the object chosen for the change, and thus formed 

 into an ovalish and flattened disk, beneath, which is 

 placed, or from which exudes, an obviously tenacious 

 fluid of a dark colour which anchors the larva to the 

 spot, aided probably by the short and stout spines 

 which sparsely clothe that region. In this position 

 it remains for a period of fully four days, gradually 

 growing darker in colour, and assuming a ruddy hue 

 along the back. On the fifth day, after a good deal 

 of very vigorous motion, during which it becomes 

 quite evident that the anteroinferior abdominal disk 

 is the only point of attachment of the larva to its 

 seat, the skin of the upper anterior portion of the 

 thorax becomes ruptured and the lively pupa vigor- 

 ously pushes itself forward out of the larval envelopes, 

 wriggling and twisting, expanding and contracting, 

 and frequently raising itself up nearly vertically in its 

 anterior three-fourths or so, until the exuviae has 

 passed beyond the fifth abdominal segment, when its 

 efforts cease, and the remaining abdominal segments 

 remain incased within the exuviae which firmly retains 

 and moors the pupa. The colour of the newly- 

 emerged pupa is pale green, variegated with pale dull 

 orange and the now nearly white dorsal mottling of 

 larvahood ; but in a few hours it has darkened — 

 become nearly black, with ruddy dorsal markings. 



The spiracles, now reduced to four pairs appertaining 

 to the first four abdominal segments, are white 

 in colour, and are much more elevated than in the 

 larva. 



In the pupa, the thoracic region is flattened out 

 horizontally all around, both laterally and anteriorly, 

 this extension having become nearly semicircular in 

 outline, and being quite thin ; and instead of being 

 surrounded with eight pairs of strong branched spines as 

 in larvahood, it is only margined with simple small 

 spines, two pairs of which, however, the fourth and 

 fifth from the mesial line anteriorly, are longer and 

 stronger, and furnished with some minute spines. 

 The pair of spines on the lateral margins or edges of 

 each of the five anterior abdominal segments (which 

 are all that can be seen, owing to the exuviae being 

 still attached to and covering and concealing the 

 remainder of the abdomen of the pupa) are also 

 flattened out horizontally quite thin, but are still 

 furnished around their margin with secondary spines ; 

 they are at the base equal in width with the segment, 

 and are directed outwardly, and inclined upwardly at 

 a considerable angle. Possibly the extraordinary ex- 

 tension of the entire margin of the thoracic region is 

 clue to a horizontal flattening-out, and a coalescence of 

 the eight pairs of spines which surrounded that region 

 during larvahood j and in the flattening-out of the 

 abdominal spines we may see the same process in 

 operation, which in the imago will be fully evolved 

 and seen in the extensive marginal addition to the 

 elytra which obtains. On the pupa first emerging, 

 the thin marginal extension of the thorax is infolded, 

 as are also the flattened-out abdominal spines, but 

 they both rapidly unfold. 



In ten days after the pupa-state has been entered, 

 the perfect beetle emerges through a breach in the 

 upper anterior portion of the pupa-case. It is at first 

 of a pale green colour above, and a fine salmon colour 

 below, with some black variations ; i.e., the protho- 

 racic shield and the elytra are of a uniform pale green, 

 and the thorax and abdomen are of a salmon colour 

 with some black variations inferiorly, the salmon 

 colour showing through the as yet only semi-opaque 

 shield and elytra, as do also the head and antennae. 

 In a few hours it has become much darker green 

 above, and is entirely shining black beneath. 



(To be continued.) 



SCIENCE-GOSSIP. 



Mr. Walter Gardiner, M.A., has just con- 

 cluded a course of three interesting lectures at the 

 Royal Institution, entitled "The Plant in the War 

 of Nature." 



We have received a reprint of the " Land and 

 Freshwater Mollusca of Leicestershire," by Mr. H.. 

 E. Quilter. 



