324 INTERNAL ANATOMY OF THE GAMASIN^. 



most mature egg is seen in a form which it often assumes, sometimes to a much greater degree, 

 when about being forced through a narrow passage^ — e. g. the entrance of the oviduct. A small 

 Ijart of the upi^er portion of the Ijrain is seen with the dark cells of the cortical layer at the 

 edge ; behind it is the oesophagus, cut through and looking like a ring, surrounded by numerous 

 portions of the tendinous platform (episternite) and the muscles proceeding from it. The cloaca is 

 cut about where the two Malpighian vessels euter, and shows a septum between. The greater part 

 of the portion of these vessels which lies iu the hinder half of the body is shown, but not the 

 bend by which they reach the cloaca. Almost the whole of the upper hind caeca of the ventri- 

 culus is shown, and nearly the whole of the right anterior caecum ; the left is cut across. 



Fig. 08. Sagittal section of the posterior portion of an adult female Hcemogamasus horridiis, cut a little 

 to one side of the median line ; x 75. It shows the sacculus fcemineus, with a portion of its 

 coruu and the commencement of one ramus lying above the ventriculus. Nearly the whole 

 length of the oviduct and vagina is shown. 



Fig. 09. Transverse section of an adult female of the same species, cut through the insertion of the fourth 

 pair of legs ; x 85. It cuts the sacculus fcemineus just at the point where the rami are starting 

 from it. The arms of the lyrate organ are cut across. 



Fig. 70. Sagittal section of an adult female Hcemogamasus hirsutus, cut a trifle to the side of the median 

 line ; X 70. It shows one of the great diverticula of the sacculus fcemineus cut through and 

 also a part of the sacculus itself. The camera spermatis is full of filamentous spermatozoa, and 

 the point where the arms of the lyrate organ join it is seen. Almost the whole length of the 

 oviduct and vagina are exhibited. 



Fig. 71. Sagittal section of an adult female Holotaspis 'iiioniivagus{?), cut precisely in the median line ; 

 X 125. The sacculus is shown with the central and a portion of one lateral chamber of the trefo il 

 (pages 304-305) ; also the tube jjroceeding from the central chamber and wholly contained within 

 the sacculus. The lyrate organ, cut through, is just behind the sacculus. An egg has the 

 embryo highly developed; a portion of the Malpighian vessels of the embryo is already functional 

 and is filled with the usual contents; it is near tlie dorsum of the embryo. This large egg has, 

 as generally happens, flattened the cloaca and pushed some of the surrounding organs somewhat 

 out of position. The wliole lengtii of the oesophagus is seen jJassing right through the brain 

 and entering the ventriculus ; one maiulibular nerve is also indicated. A salivary, or poison, 

 gland lies below the mandibular muscles. The tendinous platform (episternite) is seen almost 

 surrounded by the ventriculus. The tendency to the dome-like recess in the vagina is seen. 



Fig. 72. Transver.se section of an adult male Hcemogamasus horridus, cut between the third and fourth 

 legs ; X 120. The two great accessory glands are cut just where the large columnar cells of 

 the hinder parts of the organs are fading into the more reticulated anterior portion; the testis 

 is seen above in several l)locks, showing sperm-mother-cells in various stages. 



Fig. 73. Transverse section through the rostrum of an adult female Hmnogamasus horridus, cut near 

 the anteiior end of the pharynx; x 280. It shows the tricarinate (in section triiadiate) 

 form of the pharyngeal skeleton (page 310) and the distensor and constrictor muscles. 



Fig. 71'. Transverse section of an adult female Hfemogainasus hirsvtvs, cut through the anus; x 200. 

 It shows the levatorcs and constrictor ani muscles, &c. The creature was killed with boiling 

 water, and consequently the anus is protruded rather more than would be natural. 



