72 LECTURE VI. 



cordiform glandular body, representing a prostate or vesicula seminalis. 

 The external orifices of the male apparatus, according to Miram, 

 are two in number, and are situated on the dorsal aspect of the body 

 just behind the head. Diesing, however, describes the male Pentas- 

 toma as having only a single penis, which protrudes just behind or 

 below the oral aperture. 



The female generative organs of the Linguatula tcenioides present 

 a structure in some respects analogous to that of the Distoma 

 pcrlatum : the ovary is a part distinct from the tubular oviduct, and 

 is attached to the integument or parietes of the body, extending 

 down the middle of the dorsal aspect. It consists of a thin stratum 

 of minute granules, clustered in a ramified form to minute white 

 tubes, Avhich converge and ultimately unite to foinn two oviducts. 

 These tubes proceed from the anterior extremity of the ovary, diverge, 

 pass on each side of the alimentary canal, and unite beneath the 

 origins of the nerves of the body, so as to surround the oesophagus 

 and these nerves as in a loop. The single tube formed by the union 

 of the two oviducts above described, descends, winding round the 

 alimentary canal in numerous coils, and terminates at the anal 

 extremity of the body. The single oviduct, besides receiving the 

 ova from the two tubes, communicates at its commencement with two 

 elongated pyriform sacs, which prepare and pour into the oviduct an 

 opaque white secretion. 



The male organs in the Nematoidea consist of a single and simple, 

 slender, elongated tube {Jig. 30, e, e^,f^ or testis, under its most ele- 

 mentary form, a seminal i-eservoir, and an intromittent organ, con- 

 sisting of a single or double spiculum and its prepuce, or bursa. 



The si^iculum is simple in the genus Filaria. According to the 

 observations of Dr. Leblond, the male-duct in t\\e Filaria papillosa 

 terminates at the anterior extremity of the body, close to the mouth. 

 From this aperture the slender duct, after a slight contortion, is 

 continued straight down the body to a dilated elongated sac, which 

 represents the testis. 



In the Trichocephalus dispar the testis, a single tortuous tubule, 

 commences by a blind extremity near the rectum, passes forwards to 

 a dilated seminal receptacle at the anterior part of the thick portion 

 of the body, from which it bends backwards nearly the whole length 

 of the thick part, constricted at irregular intervals, and terminating 

 in a narrow straight canal, which is continued into the inverted 

 pyramidal appendage, or bursa, attached to the hinder extremity of 

 the body, from which the single sjjiculum projects. 



In the Strongylus gigas, the bursa or sheath of the penis, terminates 

 the posterior extremity of the body, and is a cutaneous production of 



