NATURAL HISTORY IVORK IN CART AGO 69 



Prof. R. W. Doane (1913), of Stanford University, ob- 

 served that Oryctes rhinoceros, feeding on the growing heart 

 in the crown of the cocoanut trees in Samoa, has first to pass 

 through a web-Hke sheath before it reaches the hard wood. 

 "In doing this the head is lowered and the [cephalic] horn 

 thus thrust forward. The horn becomes imbedded in the 

 tissue of the plant and when it is raised serves as an anchor 

 to hold the insect while it pulls or pushes its body forward 

 with its legs, or while it tears the tissue of the plant with its 

 heavy mandibles." Baron von Hiigel informed Dr. David 

 Sharp (1899) that in Java he had "observed large numbers 

 of Xylotrupes gideon; he noticed that the males sometimes 

 carry the females by the aid of their horns. "^ Dr. Ohaus 

 has also kindly informed us that a correspondent of his 

 friend Herr Nagel has observed, in Venezuela, that the 

 males of Dynastes hercules fight very violent battles among 

 each other for the females; that they seize and crush with the 

 cephalic and prothoracic horns, the weaker male often having 

 its thorax and elytra crushed, and that the victorious males 

 take the females between the horns and carry them away. 



One Sunday, July 25, a peon brought to A. at Cartago, a 

 male Dynastes perse^is which he said he had found in the 

 market among sugar-cane which had come from Juan Viiias. 

 He was evidently afraid of it and was glad to sell it. We 

 kept the beetle alive until August 24, most of the time in a 



' As the observations are very much scattered, it may be useful to give here the 

 exact references to the original statements. Darwin, Descent of Man, Part II, 

 Chapter X, ist ed., 1871, New York edition of 1896, p. 297. Lintner, 5//; Rept. o« 

 Injur., etc., Insects, State of New York (42d Rept. N. Y. St. Mus. Nat. Hist.), 

 1889, p. 231. Ohaus, Deut. Ent. Zeitschr., 191 1, p. 230. Bennett, Proc. Ent. Soc, 

 London, 1899, p. xiii. Doll, Bull. Brooklyn Ent. Soc, VII, p. 121, 1885. (See alsa 

 Lintner, ^tk Rept. on Injur., etc.. Insects, State of New York, p. 252, footnote t» 

 1891.) Doane, Science, n. s., XXXVIII, p. 883, 1913. Sharp, Cambridge Nat. 

 Hist., VI, p. 199, 1899. (Cf. also Cunningham, Sexual Dimorphism in the Animal 

 Kingdom, p. 254, 1900.) Andrews, Journ. Exp. Zool. xxi, pp. 435-436, 1916 ("the 

 significance of these male horns [of Dynastes tityus] remains entirely problematical "). 



