Tlic Life History of Drilus fiavescens. 4- 5 



or three hours iu tlie same preservative solution, or return 

 to its dull existence apparently unaffected by an immersion 

 of an hour and a half in whisky half diluted. 



An offensive acrid fluid is emitted from both extremities 

 of the body by the two winter forms of the larva, when 

 disturbed ; the active form does not seem to possess this 

 resource, but rolls itself into a ring. 



In Mulsant's account of the insect (" Histoire Naturelle 

 des Coleopteres de France ; Mollipennes : " pp. 422 ff.), 

 pupation is said to take place fifteen to eighteen days 

 before the imago appears. Prior to this, the position 

 within the shell is reversed, so that the head lies in the 

 direction of the orifice (in wdiich respect this second winter 

 form differs from the earlier one). In a single instance 

 this change of position had already occurred when I ex- 

 amined the shell on October 8th, but ordinarily it appears 

 to be made in the spring. At the time of pupation, the 

 skin is cast far back, near the centre of tlie spire. The 

 skin of the pupa is soft and unprotected, and merely 

 displays rather distinctly the enclosed form of the imago. 



When the final change takes place, about the middle 

 of May, the imago moves forward and occupies the inter- 

 vening space betw^een the pupa and the larva-skin of the 

 previous year, lying with its head thrust against the 

 anterior part of the latter. There are thus, at this point, 

 four stages of the insect represented in the shell. Here 

 the imago remains for some days before it is able to leave 

 the shell. In three female examples observed in the 

 present year, at least eight days were passed in this way, 

 and the case of a male, referred to below, was similar. 

 The imago appears at the end of May or beginning of 

 June, about the same time as the hibernated larva. 



The apterous female (Plate I, fig. 4} is elongate and 

 broader behind, with the abdominal segments sharply 

 explanate under the spiracles, so that the sides have a 

 scalloped appearance. It is of a tawny testaceous colour, 

 marked on each segment, except the last, with a pair of 

 large dark-brown digitate patches more or less regular in 

 shape, and thinly covered, especially above, with fine short 

 rufous hairs. The last segment is terminated by two 

 processes with a small palpiform appendage at the apex 

 of each. The supplement to the antennse found in the 

 larva and retained in both winter forms, reappears very 

 similarly in the female imago. At the apex of the tenth 



