416 LECTURE XVITI. 



such larvae are readily distinguishable by such cocoons. Von Scheven 

 secluded one of these virgin female larvae of the Psyche vestila, and 

 found that she laid only barren eggs. 



The female larv^ of certain species of Pysche live quite separate 

 from the males on peculiar feeding localities. When about to become 

 pupas, most of the cocoon-bearers leave those localities, and attach the 

 mouth of the cocoon to branches of trees, to stones, or rocks. Before 

 becoming pupae, the grub turns itself in the cocoon, and brings its head 

 opposite the hinder or lower free opening of the cocoon. The female 

 pupae manifest very little motion, but remain passive at the upper 

 end of the sac, by which it is suspended ; whilst the active male 

 pupae protrude their thorax from the lower opening of the cocoon 

 shortly before emerging as the perfect moth. The almost apodal 

 maggot-shaped females cast their pupa-skin without quitting the 

 cocoon ; they wait, in the hinder or lower free end of the cocoon, 

 the approach of the male, which accomplishes the act without ever 

 seeing the female of his choice. 



The male Psyche has not the penis of any remarkable length, but 

 he is able to elongate considerably the abdomen ; the skin of that part 

 is soft and extensible ; he inserts the abdomen into the hinder open- 

 ing of the female cocoon, and brings the external genitals into con- 

 nexion with the copulatory canal of the female. After the coitus, 

 the female, which has no ovipositor, pushes herself back again into 

 the cast pupa-skin, and there oviposits. Also, if such a female, 

 awaiting the male, be disturbed at the closed end of the cocoon, she 

 returns and betakes herself wholly within her old shed pupa-skin. 

 In the allied genus Talcsporia, the larviform females emerge from 

 the hinder aperture of their short cocoon, and creep, by means of 

 their well-developed legs, to the under side of the cocoon ; the gene- 

 rative act being performed in open day. These females have a long 

 ovipositor, and by means of it they fill their old pupa-skin with the 

 impregnated ova. The procreant female of Psyche is maggot-shaped, 

 has no fully-developed legs, no articulate antennae, nor distinct eyes ; 

 neither has she a trace of an ovipositor ; the last abdominal segment 

 consists only of a short fleshy cylinder, on which a short oviduct 

 opens. The colleterium is a double pyriform glandular sac, with a 

 short common duct. A sperraatheca communicates, by a short con- 

 voluted duct, with the common vagina, which has two lateral fleshy 

 folds, and is connected with a round bursa copulatrix, with thin and 

 delicate walls. 



Such accessories to the flabelliform ovaria and short oviducts of 

 the Psyche are of themselves sufficient to show that her ova are 



