Miscellaneous. 75 



be the case. The oval whitish body had one end turned towards a 

 thick tracheal stem close to the stigma, and this end of it was 

 pushed into a brownish chitinous cup which surrounded it, but the 

 narrow base of the cup was attached to the trachea. After removing 

 the whitish body from the cup it could be seen, that at the bottom 

 of the latter there was a small aperture leading into the trachea. 

 From the margins of the cup extended irregular translucent chiti- 

 nous deposits which surrounded the whitish oval body. On micro- 

 scopic observation of the whitish oval body aunulation was observable 

 upon it ; tubular organs (alimentary canals) shimmered through 

 from the interior ; at the end turned towards the body-cavity (of 

 the Carabus) sharp booklets were observed, and at the opposite 

 extremity two respiratory apertures. From these characters a 

 young TacJiiua-hiTYa was easily recognized in these little bodies. 

 Hoon after I obtained some specimens of Carahus cancettatus, each 

 of which was infested with several Tachina-YnxYs^, already full-grown. 

 The larva3 were so large that they filled nearly the whole ventral 

 cavity of the beetle. The beetles infested by Tachinai were dis- 

 tinguished by their sluggishness from those not so attacked, and 

 soon died in captivity. The chitinous cups which embraced the 

 hinder extremities of the large larvae were large arid had an irre- 

 gular margin ; the translucent chitinous deposits which surrounded 

 the body of the larva were greatly developed and had the form of 

 irregular and in part confluent lobes. In short, chitinous patho- 

 logical structures surrounded the body of the larva just as inflamed 

 connective formations enclose foreign bodies which have got into the 

 body of a vertebrate animal. This fact is certainly in favour of the 

 conception' of chitine as the physiological equivalent of the connec- 

 tive tissue in the bodies of insects. There is no doubt that the 

 deposition of chitine took place from the soft hypodermal layer of 

 the wall of the trachea, liesides Caralnis cancdlcdits I obtained a 

 specimen of Carahus (/labratus, which was also infested by numerous 

 larvte of Taeidna. 



I did not succeed in rearing a single fly from any of these larvsD, 

 partly because I had other purposes in view in the investigation of 

 the species of Carahus, but partly because the infested beetles did 

 not live long in confinement. I hoped to have obtained some in- 

 fested Carahi\nt\\Q summer of 1883, but none of the beetles of this 

 kind collected by me that summer contained TaclunaA&TYde.. On 

 the other hand. I found a specimen of Harpalus rujicomis which 

 was literally stuffed with these larva}. 



The occurrence of Tachina-larYse in the bodies of adult insects is 

 by no means a new fact. As long ago as the year 1828 Boheman 

 found the larvae of Uromijia curvicauda in Hariialus rujicorms and 

 H. avlicvs *. Leon Dufour has described Htjalomyia dispar, which 

 is parasitic in Bracliyderes lusitanicus'\ ; and he also found the 

 larvse of Phasia in Pentatoma grisea and Cassida viridis +, and the 

 * Stockholm Akademieus Handlingar, 1828, p. 104, 

 t Ann. Soc. Eut. Fr. 1852, p. 443. 

 X Ibid. 1848, p. 427. 



