Medical Officers of the Army of India.

49

found here In this hope I append some references to the literature of this
interesting subject:—

      Sar in Müller's Archiv f. Anat. u. Physiol. 1842 p. foll. 329, and in Wiegmann's
Archiv f. Naturges. X. 1844, i. p. 169.

      Krohn, in Müller's Archiv f. Anat. 1851, p. 338.

      Max Schultze, in Müller's Archiv f. Anat 1852, p. 37.

      Leuckart, in Wiegmann's Archiv f. Nat. XX, 1854, ii. p. 387.

      Grube, in Monatsber. K. Akad Berl. 1868, p. 178, and Ann. Mag. Nat. Hist. (4) II,
1868, p. 168.

      A. Agassiz, in Proc. Amer. Acad. Arts and Sci. (Boston) 1876, p. 231; and Ann. des
Sci. Nat., Zool., (6) v. 1877.

      Studer, in Monatsber. K. Akad. Berl., 1876, p. 452; and in Zool. Anzeiger 1880, p.
523 and p. 543; and in Abhand. K. Akad. Berl., 1832, p. 13; and in J ahrb. Hamb. Wiss.
Anstalten, 1885, p. 157.

      Wyville Thomson in The Atlantic (Voy. H. M. S. "Challenger ") Vol. II, p. 213; and
in Journ. Linn. Soc., Zool., XIII. 1878, p. 55.

      Koren and Danielssen, in Fauna Littoralis Norvegiæ III, 1877, p. 68.

      Ludwig, in Beneden and Bambeke's Archiv. de Biol. II, 1881, p. 41; and in Ann.
Mag. Nat. Hist. (6) XX, 1897, p. 327 and p. 487.

      Perrier, in Compt. Rend. CII. 1886, p. 1146.

      Recorder in Wiegmann's Archiv f. Nat. LIII. 1887, ii. pt. 3, p. 193.

      Mortensen, in Zeits. Wiss. Zool. LVII, 1894, p. 704.

      Clark, in John Hopkins Univ. Circulars, Vol. XVII. No. 132; and in Journal
Jamaica Inst. July 1896; and in Zool. Anzeiger, 1895, p. 398; and in Mem. Boston Soc.
Nat. Hist. V, 1898, No. 3, p. 53.

      2. On Secondary Sexual Characters and Pairing among Higher Crustacea.

      Among the Decapod Crustacea, although there are numerous species—even
remarkably endowed species such as those of the genus Ocypoda— in which the
sexes are quite alike, yet it is very common to find the male possessed of
chelipeds one or both of which differ very greatly in size, and often also in form,
from those of the female.

      It appears probable that in some cases the large cheliped is useful for
holding the female: in other cases it is used by rival males as a weapon, especially
at the breeding season. In Gelasimus annulipes, one of the common Fiddler-
crabs of Indian estuaries—as will be found described in the section headed Miscel-
laneous Notes on Stalk-eyed Crustacea —the enormous cheliped of the male is not
only used both as a weapon of attack and as a shield, but also, being beautifully
and conspicuously coloured, is obtrusively displayed to attract the female.

      There are other differences between the sexes in the higher Crustacea—such
for instance, as the numerous appliances possessed by the males of certain