52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I42 



sophila virilis in a nitrogen mustard solution for 30 minutes, then 

 washed and dried them. Many of the emerged adults showed mal- 

 formations of the antennal arista and the compound eyes, as well as 

 of other parts of the head and body. The antennae and the eyes of 

 muscoid flies are developed in deep pouches of the head wall (not 

 from the "pharyngeal cavity" as the above authors state. (See Snod- 

 grass, 1953). 



The effects of the treatment on the antennae varied from an arista 

 almost normal (fig. 21 F) except for the presence of two points on 

 the apex, through a series of greater modifications (G), to one that 

 somewhat resembled a jointed, two-clawed leg (H). The results 

 varied with the age of the larvae treated, being greatest between ages 

 of 70 to 78 hours. After 88 hours the antennae regenerated normally. 



The normal antenna of Drosophila virilis (fig. 21 E) consists of 

 the usual parts of a typical muscoid antenna, namely, a narrow basal 

 scape (Sep), a pedicel (Pdc), and a large lobe (ifl) bearing an 

 arista (Ar). The arista and the supporting lobe together constitute 

 a four-part flagellum, the arista having a very narrow basal ring, a 

 small second unit, and a long, branched apical shaft. It is of particu- 

 lar interest to note that in the regenerated appendage (G, H) it is 

 only the arista that assumes the leglike character. Hence the term 

 aristapedia given by Bodenstein and Abdel-Malek to these regenerated 

 antennae. 



Lengerken (1933) describes leglike antennae of a beetle, Tachy- 

 deres succinctus, found in nature. The normal antenna of this species 

 (fig. 21 A) has a large, somewhat swollen scape, a small pedicel, and 

 a long, slender flagellum of 10 subsegments. In the abnormal an- 

 tennae (B, C) the scape, pedicel, and first section of the flagellum 

 are approximately normal, but the rest of the flagellum is an irregu- 

 lar, apparently 7-segmented structure with a pair of terminal claws. 

 As in DrosopJiila the deformity affects only the flagellum beyond its 

 basal section (ifl), the proximal part of the appendage being that 

 of a normal antenna. The resulting Fiihlerbein, Lengerken observes, 

 could have no locomotor function. 



Perhaps the most leglike regenerates from amputated antennae are 

 those obtained from experiments on Phasmidae. Cuenot (1921), 

 working with Carausius (Dixippus) morosiis, amputated the antennae 

 through the middle of the scape or pedicel and obtained regenerates 

 (fig. 21 D) with a typical leg tibia, a tarsus of four tarsomeres, and 

 two apical claws with a median lobe between them. Even here, how- 

 ever, there is not a complete leg, and the large regenerated basal 



