1360 The Zoologist— September, 1868. 



long. From this it would appear to have some connection with the 

 entrance into the pupa state. 



" Their metamorphosis is known ; it takes place in earth, in roots of 

 plants, under rotten logs, or in swamps. Such moist localities are 

 selected by the heerwurm larvae after they have come to a certain age, 

 and the time of pupa change has arrived, which is known by the desire 

 for association. 



" The mucus which keeps the maggots together is a product of the 

 salivary gland in Sciara ingenua, and almost all other dipterous larvae 

 which have a head, and which make a fine cocoon. The formation of 

 pupae of the heerwurm takes place surrounded by this mucous saliva. 

 The heerwurm can be regarded as a collection of larvae, for the 

 purpose of mutual transformation ; that is, it is accomplished through 

 mutual protection as a period favorable to development. This con- 

 nection is given up before the formation of nymphs really arrives, the 

 individuals separating, from time to time, in search of food. When 

 now the larvae of large divisions of Diptera, as the Pupipares, 

 Notacanthes, &c, have the peculiarity of changing their own skin into 

 a cover, which is the grave of the larva and the cradle for the pupa ; 

 and the larvae of another division of the Diptera, as the Tanystomes 

 and the Nemoceres, before changing, strip off their cover, and are 

 transformed free or in a cocoon, so the Sciara Thomae presents a 

 process intermediate between these, as the construction of the cocoon 

 is not performed within the skin of the larva itself, but in a cavity 

 which is made of the skins of numbers of other larvae." 



There appears, however, to have been no record of the observation 

 of this peculiar habit of larvae in North America, up to within a short 

 time. The genus is known to exist here, and Osten Sacken (/. c.) 

 describes a species which he calls Sciara toxoneura. Hence the 

 following account, which I have received from my friend William Kite, 

 teacher at Westtown School, in Chester county, Pa., is of considerable 

 interest. The statements are those of a careful naturalist, well 

 acquainted with the field and field study. Before quotiug it, it must 

 be noted that another account of the same phenomenon was published 

 in 'The Friend' journal (Philada., 1864), by Charles Potts, another 

 teacher in the same excellent institution. Some statements of this 

 writer need correction, as farther observation convinced him : e.g. that 

 they could climb. 



The following are observations of Wm. Kite : — 



" On the morning of Ninth Month, 11th, 1866, a company of worms 



