232 CLASS vn. 



bekannte arten aus der Familie der Regenwilrmer, mit Zeichnungen 

 nach dem Leben. Braunschweig, 1845, 4to. 



On the anatomy compare MONTEGRE Observations sur les Lom- 

 brics ou vers de terre, Mem. du Museum, I. 1815, pp. 242 248, PL 

 12 ; J. LEO De structurd Lumbrici terrestris, Regiomonti, 1820, 

 4to, cum Tab. cen. ; C. F. A. MORREN Commentatio de structura 

 anatomica et historia naturali Lumbrici vulgaris sive terrestris 

 (Annal. Acad. Gandavensis), Gandavi, 1829, cum tabulis, &c. 



The setse are short and rigid, in every ring 8, on each side two 

 pairs, so that eight rows run longitudinally on the body, four laterally, 

 and four beneath ; in Hypogceon SAV. there is moreover another 

 row of single hairs in the middle of the back. The intestinal canal 

 is straight, with a membraneous pyriform proventriculus and a round 

 or spherical muscular stomach ; behind the stomach it is divided by 

 many transverse folds into blind pouches, which further back are 

 less developed, where also the intestinal canal becomes smaller 

 though on the whole it is wide throughout. In the interior of the 

 canal on the dorsal side is a band, which begins a little behind the 

 stomach, at this anterior end, as also at the posterior, runs to a 

 point, and consists of two membranes, of which the external is 

 yellow, the internal white ; intestinum in intestino WILLIS, typhlo- 

 sole MORREN. This enigmatical part is probably a duplication of 

 the membrane of the intestine, an internal mesentery (MORREN) ; it 

 may be compared with the valvular membrane of certain sharks *. 

 To the sexual organs belong in the first place three pairs of grey- 

 yellow saccules which are situated in the anterior part of the body 

 (in the common large earth-worm, Lumbricus agrieola HOFFMEISTER, 

 in the eleventh, twelfth, and thirteenth ring), and of which the 

 posterior pair is the largest. These parts are usually considered to 

 be ovaries, but STEENSTRUP, who here also denies Hermaphroditism, 

 supposes them to be testes in which the seed is formed with the 

 spermatozoa in cells, that may be readily mistaken for eggs. 

 H. MECKEL maintains that these organs are in all individuals testes, 

 and says, that the ovaria, intimately conjoined with them, lie like 

 a brown-yellow lobe on each of these saccules. Four small vesicles, 

 resembling barley-corns, placed more laterally (two on each side), 

 contain in the pairing season a white fluid with spermatozoa free 

 and developed : by most writers they have been signalised as the 



1 Perhaps also it is furnished with a vessel ( Vena mesenterica interior] ; see 

 DUVERNOY in the second edition of CUVIER, Le$. d'Anat. comp. Tom. v. 1817, p. 335. 



