Report of the State Entomologist. 247 



larva, as of a species of fly or other insect, it usually enters the 



body through the joints of the legs, and becomes encysted, or inclosed 



in a small sac or bladder, as are the 



Trichinae. When these larvae are eaten 



by fish the cyst is broken and the 



Gordius passes to its second stage. 



After having remained free in the body 



for a while, it again becomes encysted 



in the mucous layer of the intestines. "'^^^^ t"^^ 



In its third stage it is again free, when ^^^ 52.- ThT young Gord^ 



it penetrates into the intestines of the varius, after emerging from the 



fish whencp it na^MPM with tlip ffpce^ into ®^^' allowing different degrees of 

 nsn, wnence it passes witn tne t»ces into protrusion of the oral apparatus. 



the water, where it enters upon its final (After Leidy.) 

 growth, undergoing other changes. Such is its history when enter- 

 ing into aquatic larvse, as elaborated a few years ago by M. A. Villot, 

 a French scientist. Its subsequent changes, when parasitic upon 

 terrestrial insects have not been as fully observed, and just how, at 

 maturity, it succeeds in entering their bodies, is still a mystery. 



Mermis Parasitic on the Apple-worm. 



The other genus of hairworms, Mermis, has occasionally been found 

 within apples, where it occurs as a parasite of the apple-worm, the 

 larva of the codling moth, Garpocapsa pomonella. A notice of Mermis 

 acuminata occurring in some apples in Orange county, N. Y., in 1875, 

 coiled up in the fleshy part of the fruit, about midway between the 

 skin and the core, was given by me in the Thirtieth Annual Report on 

 the K Y. State Museum of Natural History for the year 1879 (pp. 117-126); 

 also in my Entomological Contributions (No. iv, pp. 5-14). It is therein 

 mentioned that a species of Mermis infests the Garpocapsa pomonella 

 larva, in Europe. According to Dr. Speyer, the Gordiaccea not unfre- 

 quently occur in larvse which feed on tall trees, as well as those which 

 live on plants and shrubs. Wet seasons seem to be productive of the 

 parasitism, and Dr. Speyer recalls a number of years ago, his having 

 met with several of such instances. From an example of Hadena 

 adusta, he had a Mermis emerge of the length of eight and a half 

 inches, and another from Hesperia lineola after it had been pinned. 

 Prof, von Siebold suggests that a heavy dew may so moisten the 

 trunks of trees as to enable the Mermis to ascend them. 



Those who would know more of these interesting creatures, may 

 find an excellent extended article upon them in the First Report 

 of the U. S. Entomological Gommission, 1878, pp. 326-333, from which 

 the illustrations herewith presented have been taken. 



