ACANTHOOEPHALA 257 



domesticated. According to Schneider the embryos take up 

 their residence in the grubs or larvae of the cockchafer (Melo- 

 lontha vulgaris), a discovery which very readily explains the 

 manner in which hogs become infested. Whether E. gig as be 

 a human parasite or not, it is certainly very injurious, not to 

 say destructive, to swine. Although this parasite must be 

 quite common in England I have experienced great difficulty 

 in procuring specimens. In the second book of this work I 

 shall give some interesting particulars furnished by the memoir 

 of Prof. Yerrill and privately by Mr George Wilkins. (See 

 ' Parasites of the Pachydermata'.) 



BIBLIOGRAPHY (No. 35). Blanchard, in ' Cuvier's Eegne 

 Animal/ tab. 35 (good fig.), and in ' Ann. d. Sci. Nat./ ser. xii. 

 Bremser, ' Icones/ tab. vi. CobboJd, " Parasites of the Hog," 

 the ' Veterinarian/ 1875. Idem, ' Manual/ 1. c., p. 123. 

 Davaine, 1. c., ' Syn./ p. 83. Diesing, 1. c., ii, p. 2. Dujardin, 

 1. c., p. 503. Goeze, 1. c., s. 143 (good figs.). Gurlt, 1. c., 

 s. 367. Heller, ' Darmschmarotzer/ 1. c., s. 663. Lambl, 1. c., 

 supra; Feb., 1859Leuckart, 1. c., Bd. ii, s. 729; also in ' Bibl. 

 Univ.' for March, 1863, and in ' Ann. Nat. Hist./ vol. xii, 1863. 

 Owen, 1. 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., 1. 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. PAKT II. SUCTOEIA (Leeches) 



As explained in the Introduction we must regard the Leeches 

 and many allied forms of Suctorial Annelids as creatures pos- 

 sessed of semi-parasitic habits. They are, perhaps, something 

 more than what Van Benedeii styles "free parasites " an expres- 

 sion 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 mcdicinalis, Savigny), the green-leech (8. officinalis, 



17 



