INSECTS. 339 



states that, " male specimens can be found in the same 

 locality in which the central horn of the thorax is very 

 large, but the horns of the head quite rudimental ; and 

 others, in which the thoracic horn is much shorter, while 

 the protuberances on the head are long."* Here we appar- 

 ently have a case of compensation, which throws light on 

 that just given, of the supposed loss of the upper horns by 

 the males of Onitis. 



Law of Battle. Some male beetles, which seem ill-fitted 

 for fighting, nevertheless engage in conflicts for the posses- 

 sion of the females. Mr. Wallace f saw two males of 

 Leptorhynclms angustatus, a linear beetle with a much 

 elongated rostrum, " fighting for a female, who stood close 

 by busy at her boring. They pushed at each other with 

 their rostra, and clawed and thumped, apparently in the 

 greatest rage." The smaller male, however, " soon ran 

 away, acknowledging himself vanquished." In some few 

 cases male beetles are well adapted for fighting, by possess- 

 ing great toothed mandibles, much larger than those of the 

 females. This is the case with the common stag-beetle 

 (Lucanus cervus), the males of which emerge from the 

 pupal state about a week before the other sex, so that 

 several may often be seen pursuing the same female. At 

 this season they engage in fierce conflicts. When Mr. A. 

 H. Davis \ inclosed two males with one female in a box 

 the larger male severely pinched the smaller one until he 

 resigned his pretensions. A friend informs me that when a 

 boy he often put the males together to see them fight, and 

 he noticed that they were much bolder and fiercer than the 

 females, as with the higher animals. The males would 

 seize hold of his finger if held in front of them, but not so 

 the females, although they have stronger jaws. The males 

 of many of the Lucanidae, as well as of the above-men- 



* "Modern Classification of Insects," vol. i, p. 172; Siagonium, p. 

 172. In tlie British Museum I noticed one male specimen of Siago- 

 nium in an intermediate condition, so that the dimorphism is not 

 strict. 



f " The Malay Archipelago," vol. ii, 1869, p. 276. Riley, Sixth 

 "Report on Insects of Missouri," 1874, p. 115. 



J " Entomological Magazine," vol. i, 1833, p. 82. See also on the 

 conflicts of this species, Kirby and Spence, ibid., vol. iii, p. 314; and 

 Westwood, ibid., vol. i, p. 187. 



