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Cincinnati Society of Natural History. 



tions are capable of producing identical structures, and sometimes the 

 same conditions are capable of producing the most varied structures. 

 Thus, as an example of the first case, I need only allude to the fact that 

 there is so little difference between the antenme and mouth parts of 

 the larvae of some of the highest groups feeding externally on vegeta- 

 tion, and others feeding in leaves on the soft parenchyma, or boring in 

 hard woody tissue, or in woolen goods, etc. Of the second case (the 

 same conditions with diverse structures), take a larva of Litho collet is, 

 feeding in an oak leaf, and of a Tischeria, feeding in the same leaf, as 

 not infrequently occurs. The burrows or mines may resemble so much 

 that only an expert would observe the difference: both species feed 

 only in leaves of the same species of plant, or in those of closely re- 

 lated species of the same genus; the entire larval and pupal life of each 

 is spent in its mine or burrow; and all of this has been equally true of 

 their ancestors for untold ages; yet how diverse are some of their struc- 

 tures: witness fig. 19, the maxilla of the Tischeria, totals unlike any 

 other known maxilla of a lepidopterous larva, and much like the same 

 organ in some Coleoptera — compare this I say with fig. 20, the same 

 organ in the Lithocolletis larva, and differing only in the minutest de- 

 tails from that of a carpet-eating Tinea, fig. 25, or Platysamia cecropia, 

 fig. 26. Such instances might be multiplied indefiniteh', not only as to 

 the maxillae, but as to all the tropin, and more especially as to the larval 

 antennas, as to which there is still more uniformity than is found in 

 the trophi. The figures (plates 1, 2 and 3) are selected from a great 

 many dissections so as to show the greatest amount of diversity that I 

 have found in these organs, in the whole order; and yet, with the excep- 

 tion of half a dozen geuera, what uniformity of form and structure is 

 found, and how very little that form and structure seems to depend on 

 the external conditions of existence of the larva. Perhaps the great- 

 est differences are to be found, as might be expected, in the mandibles; 

 and } T et even here compare figs. 33 and 34 (mandibles of the Lithocol- 

 letis and Tischeria feeding in the soft parenchyma of the same leaf) 

 with fig. 35 (mandible of Prodoxus feeding in the hard wood of Yucca 

 stems). Indeed, the mandible of Lithocolletis, seems in proportion to 

 the size of the larva as powerful an instrument as that of Pier is 

 (fig. 45) or Tinea (fig. 39), and is more formidabiy armed with teeth 

 than that of an Arctia (fig. 42). The mandible of Lithocolletis is 

 better comparable with that of Thiridopteryx (fig. 41), while that of 

 Bedellia somnutentella (fig. 40) is armed with a double row of teeth 

 placed obliquely to each other, and is one of the most formidable man- 



