Pomona College Journal of Entomology 697 



hiidy of tile l.irvii'. it was lomid that tlicy were a])])arc'iitl\' as liappv as il' it wrr<' 

 |)uri- pctroliiiiM. I'Or instance, pctrolcuMi was mixid uilli kerosene, lialf and 

 half, with xylol, benzine, cIom' oil, cedar oil, and tur])entine, and none of these 

 mixtures had any :i))parent e\ il effect upon the larva', even after they had been 

 in the li(|nids for as loni; as four or five days. Beyond I his leufith of time the 

 test was not made, but I have no doubt but that lar\a' could he reared to maturitv 

 in any of the above eonibinations with ))etroleuni. 



Animal and ])laMt life seems to be able to ad.apt itself to almost any con- 

 ceivable conditions of environment, and this instance only adds one more illus- 

 tration, tliough a most extraordinary one, to the list which is already long. Both 

 to the |)0]iular reader who is always interested in "stranjfc" thinfrs, and to the 

 man who is interested in all evolutionary adaptation, this study should be of 

 both interest and value. 



Explanation of Figure 



A. Tracheal .system of larv.i, dorsal view, show-ins; two pairs of s))iracles .and 



connecting trachcK, 



B. Lateral view of posterior ])ortion of same, showing inferior branch. 

 ('. Posterior |)ortion of one segment, showing chitinous s])ines on surface. 



D. Section through ])Osterior spiracular process, enlarged, showing three 



stigmata. 



E. Cross section of tracheal tube between stigmata and sac, showing heavily 



chitinized wall .and internal cilia. 



F. Anterior spiracle, with retraction begun, 



G. Tip of same, more enlarged, showing facetted stigmata. 



H. Terminal view of posterior spiracular process, showing five stigmata and 

 four ciliate fans. 



I. Epithelial cell of ventriculus greatly enlarged, showing large nuclei and 

 vacuoles. 



J. Cross section of ventriculus, showing imier invagination (?) with lumen 

 collapsed. 



K. Longitudinal section of ))roventriculus and ventriculus to its first turn, 

 showing what aj)pears to be an invagination of the lateral wall. (cf. de- 

 scription in text). 



Bibliography 

 1879 Hagen, H. — Flies in a Petroleum Lake, Santa Cruz County, California. 



Proc. Boston Soc. Xat. Hist., XX, p. 13i. Probably a true Ephydra 



breeding in brackish, water of lake, not in petroleum. 

 1899 Howard, Dr. L. O. — Life-history and figures of same. Scientific American, 



p. 8 (copied above). 

 1899 Howard, Dr. L. O. — Life-history and figures of same. Scientific American, 



LXXX, p. 15 (resume given above). 

 1899 Howard, L. O. and Co<iuillet — Mention of same. Entomologist, p. "235, 



Other works consulted 



LOKI Williams, F. X. — Anatomy of the Larva of Ceciilomi/ia resinicoloides Wil- 

 liams. Ann. Ent. Soc. Am., III. \)\i. f.'j-.^?. (A midge living in exuded 

 pine resin). 



1911 Shafer, Geo. D. — How Contact Insecticides Kill. Mich. Agric. Coll. Exp. 

 Station, Tech. Bull. II. 



