32 PARTHENOGENESIS IN SOME 



Bremi's collection at Zurich I saw specimens of this sac, which 

 had been sent from Ticino and the Valais. By the kindness of 

 Dr. Rosenhauer of Erlangen, I obtained a spiral sac, which was 

 found near Malaga in Spain, and which, from its size, probably 

 belongs to a species distinct from Psyche Helix. The form of 

 this sac is exactly the same, but its breadth is 3 lines and its 

 height 2J lines. 



The caterpillar of Psyche Helix selects various plants for its 

 nourishment. On the Schlossberg near Freiburg it feeds upon 

 Artemisia vulgaris. According to Zeller's testimony it also lives 

 upon Anthyllis vulneraria, Lotus corniculatus, and Gnaphalium 

 arenarium. Kollar found his on Atriplex laciniata. Near Ratis- 

 bon I observed these sac-bearing caterpillars feeding upon 

 Alyssum montanum and Teucrium Cham&drys. It is also stated 

 by Bruand, that besides Cheiranthus odoratus and Scabiosa 

 arvensis, this Sac-bearer was most frequently met with upon 

 Teucrium Chamaedrys. Reutti fed these caterpillars with Lamium 

 purpureum, and I myself supplied them with Lotus corniculatus 

 and Hippocrepis comosa. These Sac-bearers are leaf-miners 

 after the fashion of the caterpillars of Coleophora, pushing their 

 bodies far in between the epidermic plates of the leaves, through 

 a round hole which they gnaw in the latter, and devouring the 

 chlorophyll all round them, during which process the sac re- 

 mains outside sticking with its aperture to the opening in the 

 epidermis. The leaves, and even the variegated flowers of the 

 food-plants are in this way often completely decolorized by the 

 Sac-bearers. The caterpillars of Psyche Helix are of a dirty 

 white colour; the head, the legs, the three thoracic segments, 

 and the extremity of the abdomen possess a hard, blackish- 

 brown integument. The constrictions of the thorax and also its 

 median line are colourless (figs. 2, 4, 6 & 7). When taken out of 

 the sac, the caterpillar, in creeping about, retains the same 

 gentle spiral curvature of the body as when within the sac. 

 When these Sac-bearers are full-grown, which is the case in 

 the latter part of the summer, they quit their food-plants like 

 the other caterpillars of the Psychida and seek a suitable place 

 for their change to the pupa state. When they find stone walls 



de la Societe d' 'Emulation du Doubs, Annee 1852, p. 74. pi. 2. fig. 48 b (sac of 

 Psyche Helix}. 



