BIBLIOGRAPHY (No. 35).--_Blanchard_, in ‘Cuvier’s Règne Animal,’ tab. 35 (good fig.), and in ‘Ann. d. Sci. Nat.,’ ser. xii.--_Bremser_, ‘Icones,’ tab. vi.--_Cobbold_, “Parasites of the Hog,” the ‘Veterinarian,’ 1875.--_Idem_, ‘Manual,’ l. c., p. 123.--_Davaine_, l. c., ‘Syn.,’ p. 83.--_Diesing_, l. c., ii, p. 2.--_Dujardin_, l. c., p. 503.--_Goeze_, l. c., s. 143 (good figs.).--_Gurlt_, l. c., s. 367.--_Heller_, ‘Darmschmarotzer,’ l. c., s. 663.--_Lambl_, l. c., _supra_, Feb., 1859.--_Leuckart_, l. c., Bd. ii, s. 729; also in ‘Bibl. Univ.’ for March, 1863, and in ‘Ann. Nat. Hist.,’ vol. xii, 1863.--_Owen_, l. c., in ‘Todd’s Cyclop.’ (figs. after Cloquet).--_Rudolphi_, ‘Synops.,’ pp. 63 and 310.--_Schneider_, in ‘Arch. f. Anat. und Phys.,’ 1868.--_Idem_, in ‘Sitzungsb. der Oberhess. Gesellsch. f. Nat.,’ &c., 1874 (quoted by Leuckart); see also ‘Ann. Nat. Hist.,’ 4th series, vol. vii, p. 441, 1871.--_Verrill_, ‘The external and internal Parasites,’ &c., l. c., p. 109.--_Welch_, “The presence of an Encysted Echinorhynchus in Man,” ‘Lancet,’ Nov. 16, p. 703, 1872.--_Westrumb_, ‘De Helm. Acanth.’ (good figs.), 1821. SECTION IV.--PART II.--SUCTORIA (Leeches) As explained in the Introduction we must regard the Leeches and many allied forms of Suctorial Annelids as creatures possessed of semi-parasitic habits. They are, perhaps, something more than what Van Beneden styles “free parasites”--an expression which almost looks like a contradiction of terms. I cannot here, however, stop to discuss questions which lie, as it were, on the border-land of parasitology. Three species of leech are more or less commonly employed in medicine. These are the grey leech (_Sanguisuga medicinalis_, Savigny), the green-leech (_S. officinalis_, Sav.), and the dragon-leech (_S. interrupta_, Moq.-Tandon). The two former abound in Central and Southern Europe, being also present in North Africa, the last named inhabiting Barbary and Algeria. So abundant are leeches in the country bordering the Mediterranean that during the invasion of Egypt by Napoleon the French soldiers suffered seriously from their attacks. When the men lay down to drink, the leeches (_Hæmopis sanguisorba_, Sav.) affixed themselves to their mouths and nostrils, producing serious distress. They also attacked horses, camels, and cattle. In like manner the Ceylon and Philippine Island leeches (_S. ceylonica_, Moq.-Tand., or _S. tagalla_, Meyen), of which there are several varieties, prove exceedingly troublesome to Europeans. These leeches, not being aquatic forms, occupy woods and damp places. Unless the limbs of travellers are well protected, the presence of the blood-suckers is soon discovered by the trickling of blood from the limbs and lower part of the body. The leeches even sometimes creep up to the neck and other adjacent parts. These “free parasites” also attack horses, causing much loss of blood. Terrestrial leeches abound more or less in all warm countries. Sir J.