( cixxiii ) 



pencil of brownish white hairs resting on the inner side of 

 the scent-patches. The outer black hairs were spread out 

 Ian wise, accurately covering the patch, the foremost hairs 

 pointing towards the head of the insect, the middle hairs at 

 right angles to the mid-line of the body, and the hindmost 

 hairs pointing directly back. The abdomen of the insect at 

 the junction of the 10th and 1 1th segments was strongly ante- 

 flexed, the 9th and 10th segments being tumid, the 11th and 

 12th markedly constricted, an effect due, I thought, probably 

 to the strong tonic action of a detrusor muscle concerned 

 with the anal tufts. The butterfly remained motionless for 

 some seconds in this attitude, and then regular but sudden 

 movements of the wings took place, the fore-wings being 

 approximated and then over-extended, the hind-wings follow- 

 ing to about half-approximation and then also being over- 

 extended. By this means a slight movement of the black 

 hairs over the scent-patches only was effected. The operation 

 took place 10 or 12 times in half as many seconds, and then, 

 the tufts being withdrawn, the butterfly leisurely approximated 

 its wings and flew away. 



"' I found that almost as many males as I followed, old 

 worn specimens as well as fresh ones, eventually settled and 

 performed the same operation, which I studied in several 

 more. One, an old damaged insect, which had settled on a 

 leaf, extruded its right white tuft, but could not at first 

 manage to get out the left. I could see peristaltic waves of 

 contraction passing down the last three segments of its ante- 

 flexed abdomen, for half a minute to no purpose. The violent 

 expulsive efforts then resulted in the extrusion of the two 

 tufts, but even then it was only able to spread the black hairs 

 of the left tuft over the corresponding patch. The brownish 

 white tuft did not appear. The subsequent movements were 

 as in the first-mentioned butterfly. It flew away after a 

 time and again endeavoured to exsert the paler tuft, but 

 unsuccessfully. 



'" I then followed a second male and timed the operation 

 by the second-hand of my watch. From the first extrusion 

 of the tufts to their complete retraction lasted 1 minute, 

 40 seconds. These butterflies were so intent on their toilet 



